[2025] IEHC 190
THE HIGH COURT
JUDICIAL REVIEW
[2024/1296JR]
BETWEEN:
AER LINGUS LIMITED
APPLICANT
AND
THE IRISH AVIATION AUTHORITY
RESPONDENT
AND
DAA PLC AND AIRPORT COORDINATION LIMITED
NOTICE PARTIES
___________________________
[2024/1299 JR]
BETWEEN:
RYANAIR DESIGNATED ACTIVITY COMPANY
APPLICANT
AND
THE IRISH AVIATION AUTHORITY
RESPONDENT
AND
DAA PLC AND AIRPORT COORDINATION LIMITED
NOTICE PARTIES
[2024/1297 JR]
BETWEEN:
AIR TRANSPORT ASSOCIATION OF AMERICA, INC. (TRADING AS AIRLINES FOR AMERICA),
DELTA AIR LINES, INC.,
JETBLUE AIRWAYS CORPORATION AND
UNITED AIRLINES, INC.
APPLICANTS
AND
THE IRISH AVIATION AUTHORITY
RESPONDENT
AND
AIRPORT COORDINATION LIMITED,
RYANAIR DESIGNATED ACTIVITY COMPANY,
AER LINGUS LIMITED AND
EMERALD AIRLINES IRELAND LIMITED
NOTICE PARTIES
JUDGMENT of Mr. Justice Barry O'Donnell delivered on the 2nd day of April, 2025
INTRODUCTION AND BACKGROUND
1. This is a ruling on applications for injunctions that have been made in the above judicial review proceedings (collectively described as the S25 proceedings). Following an exchange of affidavits and legal submissions, the application was heard on Friday, the 28 March 2025.
2. In common with earlier applications that have been dealt with by the court in these proceedings, the court was grateful for the extremely focused approach adopted by the parties. The application raised issues of real significance to the parties and there are serious and genuine disputes about many elements in the case and applications. Notwithstanding those disputes, the parties presented their arguments in a concentrated and effective manner that was of real assistance to the court.
3. The essential background to and context for the underlying proceedings are set out in two judgments that have been given by this court. This judgment is intended to be read in conjunction with those two judgments. There is a considerable overlap between the issues canvassed in this application and those addressed in the earlier judgments. The immediate backdrop to this application was the need for clarity around what considerations could be factored into a process that will commence shortly and which will lead to the setting of coordination parameters for the Winter 2025 season. Given the need for clarity as soon as possible, I am proceeding on the basis that matters discussed and described in the earlier judgements should be taken as read for the purposes of this judgment.
a. In the first judgment, dated the 4 November 2024 and with citation [2024] IEHC 624, the court imposed a stay on the Passenger Terminal Parameters (seasonal) identified in the Appendix to the Summer 2025 Coordination Parameters as a scheduling limit for the Summer 2025 Season at Dublin Airport, which imposed a Passenger Air Traffic Movement (PATM) seat capacity of 25.2 million seats for the purposes of the Slot Allocation List. This Slot Allocation List was then due to be published no later than the 7 November 2024 by Aircraft Coordination Limited (ACL), pending the determination of these proceedings.
b. The second judgment, with citation [2024] IEHC 758 is a ruling of the court dated the 11 December 2024 which explained that the court was referring a series of questions to the Court of Justice of the European Union pursuant to article 267 of the TFEU. The ruling appended the text of the reference.
4. As explained in those judgments, the underlying judicial review proceedings concern decisions made by the Irish Aviation Authority (the IAA) pursuant to Council Regulation (EEC) No. 95/93 of 18 January 1993 on common rules for the allocation of slots at Community Airports (the Slot Regulation).
5. Under the Slot Regulation, the IAA is required to set coordination parameters for Dublin Airport. Briefly, coordination parameters are directed to ensuring the fair and efficient allocation of available landing and take-off slots in a Community airport, where the demand for those slots exceeds supply. The IAA is required to set coordination parameters biannually and in respect of what are described as the Winter and Summer seasons. The Winter season runs from October to March, and the Summer season runs from March to October. Given the need for adherence to the statutory process and the need to ensure that the airport and airlines have adequate advance notice of the slot allocation, in practical terms the window of opportunity to complete the process - and to bring any challenge to the final decision - is quite narrow.
6. The process that leads to the setting of coordination parameters involves a number of stages, including consultation with the airport coordination committee. The coordination committee for Dublin Airport comprises daa, AirNav Ireland and representatives of airlines that operate at the airport. daa acts as the chair of the committee and the IAA and ACL attend as observers. Once the IAA has set the coordination parameters, ACL engages in the practical process of slot allocation. The overall process incorporates a relatively high level of consultation at almost every stage.
7. In setting coordination parameters, the IAA is required by article 6 of the Regulation to take account of "all relevant technical, operational and environmental constraints as well as any changes thereto".
8. While the underlying proceedings canvass a range of issues, a central issue in the proceedings is a dispute as to whether certain planning conditions constitute "relevant technical, operational and environmental constraints" for the purposes of article 6.
9. The planning conditions in question were attached by An Bord Pleanála to two permissions granted to daa in relation to Terminals 1 and 2 at Dublin Airport. Those conditions mandate that the combined capacity of the two terminals should not exceed 32 million passengers per annum unless otherwise authorised by a further grant of planning permission. Those conditions are described as a the 32mppa conditions. It must be emphasised that the 32mppa conditions are not the subject of challenge in these proceedings.
10. The IAA formed the view that the 32mppa conditions constitute Article 6 constraints. Accordingly, the IAA considered that it was necessary to have regard to those conditions in setting the coordination parameters, and in turn this led to the imposition of the Passenger Air Traffic Movement (PATM) seat caps as part of the coordination parameters. As explained in the papers before the court, regardless of whether it was lawful to do so, taking account of the 32mppa conditions is a challenging practical exercise. There is some level of dispute about how the 32million figure should be calculated, for instance whether transit passengers who never leave the terminal should be included. In addition, the 32mppa conditions apply on an annual basis whereas the IAA is required to set coordination parameters biannually, and the Winter season will straddle the end of one calendar year and the start of the next year. That presents a further practical challenge to the methodology for taking account of the annual 32mppa conditions in a biannual process.
11. In setting the coordination parameters for the Winter 2024 season, the IAA imposed PATM seat caps of 14,405,737 passengers. For the Summer 2025 season, a PATM seat cap of 25.2 million passengers was imposed. Ryanair, Aer Lingus and daa commenced judicial review proceedings in respect of the Winter 2024 decision. Ryanair, Aer Lingus and Air Transport Association of America inc (A4A) commenced judicial review proceedings challenging the Summer 2025 decision.
12. The position of the parties in the underlying litigation has been set out in the earlier judgments. Put very briefly, the IAA stood over its decisions and contends that it was obliged to treat the 32mpaa conditions as an article 6 constraint. daa agrees that the 32mppa conditions constitute an article 6 constraint, although it disagrees with the manner in which the IAA has approached the 32mppa conditions in setting coordination parameters. daa take the view that the IAA is not permitted to set coordination parameters that could lead to any breach of the 32mppa conditions. The airline applicants take the strong view that the 32mppa conditions cannot constitute relevant constraints for the purposes of article 6 of the Slot Regulation.
13. In the context of what are described as the Summer 2025 proceedings, being the three sets of judicial review proceedings in the title to this judgment, the parties each sought interlocutory orders from the court staying the part of the decision of the IAA that imposed a PATM cap of 25.2 million passengers.
14. As explained in the judgment given on the 4 November 2024, the court concluded that the part of the Summer 2025 decision that imposed a PATM cap of 25.2 million passengers should be stayed.
15. For the reasons explained in this judgment I have concluded that the interlocutory relief sought by the airlines (and not objected to by the IAA) should be granted. As I will explain my view is that, subject to the parties having liberty to apply, the balance of justice favours a situation in which decisions made by the IAA in setting the coordination parameters should not take account of the 32mppa conditions. I have proceeded on the basis that the same logic and legal considerations that led to the November 2024 stay should apply to this application. That required a balancing exercise to be undertaken to the various factors identified by the parties and addressed in that judgment.
16. However, it is necessary to reassess the balancing exercise to analyse the implications of two factors: (a) the fact that this application concerns decisions that have yet to be made and where the statutory process has not concluded– as opposed to an application concerning a decision that was reached at the conclusion, and (b) the fact that to some extent the factual background may have altered since the November 2024 judgment. In that regard, daa correctly has submitted that in any balancing exercise a change in the underlying factual situation necessarily can have the effect of altering the overall balance.
17. Hence it is necessary to consider what changes have occurred since November 2024 and what effects if any those changes may have on the overall balance of justice.
EVENTS FOLLOWING THE NOVEMBER 2024 DECISION
18. As noted in the November 2024 judgment, the various judicial review proceedings had been scheduled for hearing in December 2024. It became apparent prior to the hearings that there was no realistic prospect of determining the issues in those proceedings without the benefit of having certain legal questions addressed by the CJEU. Hence, to avoid the costs and inefficiency of what would amount only to a part and necessarily inconclusive hearing, the parties agreed that the court should be requested at that point to refer questions to the CJEU. This is what occurred, and the process and questions are explained in the ruling and appended referral from the 11 December 2024.
19. One of the results of that course of action was that while there was clarity around how the Summer 2025 coordination parameters were to be operated, the IAA was required to commence the process that would lead to the setting of subsequent seasonal parameters. For those processes, pending the determination of the referral to the CJEU and the determination of the proceedings in the High Court, there remained a dispute about the imposition of PATM seat caps for the seasons after Summer 2025.
20. On the 11 February 2025, the solicitors for Ryanair wrote to the other parties proposing that, pending the determination of the substantive issues, consideration of the 32mppa conditions by IAA in setting coordination parameters should be stayed. There was an exchange of correspondence. The outcome was that the other airlines agreed to the Ryanair proposal; the IAA adopted a neutral position (but did not object); and daa did not agree. The parties therefore returned to court and a timetable was fixed for the hearing of this application.
21. The order sought is as follows:
"That the Respondent shall not, pending the determination of these proceedings and the related High Court proceedings bearing Record Numbers 2024/920JR; 2024/927JR; 2024/928JR; 2024/1297JR and 2024/1299JR (the "Proceedings"), take account of Condition 3 of planning permission FO6A/1248 (An Bord Pleanála Reg. Ref. PLO6F.220670) or Condition 2 of Planning Permission FO6A/1843 (An Bord Pleanála Reg. Ref. PLO6F.22346) (the "32mppa Conditions"), for the purposes of setting coordination parameters or otherwise in respect of the Respondent's functions performed under Council Regulation (EEC) No 95/93 of 18 January 1993 on common rules for allocation of slots at Community Airports, as amended."
22. The positions of the parties in respect of this proposal largely mirrored their positions in relation to the November 2024 stay application. The airlines sought the relief. The IAA was neutral in relation to what had been sought by the airlines, but made clear that if the relief was granted it would not prevent the otherwise orderly progress and setting of coordination parameters. Likewise, ACL adopted a neutral position.
23. The daa opposed the granting of the relief sought. Their position appeared to evolve somewhat from the position in their written submissions to that agitated at the hearing. Initially daa had questioned the jurisdiction of the court to grant the relief sought, but later restricted itself to arguing why the court should not exercise that jurisdiction. Principally this was focused on two issues.
24. First, it was argued that there was a significant difference between on the one hand staying a decision that had been made following the full statutorily mandated process and on the other hand making orders that affected a decision that had yet to be made and where the process was still in train. The argument was that the court should allow the process to work its way through to a position where the IAA made its decision, at which point challenges could be entertained. That submission proceeded from a principled argument that a court should be very reluctant to interfere in a process mandated by statute. It also encompassed a practical argument that the court would be better equipped to appraise an application to stay a decision once it was aware of all the factors and considerations, including input from third parties and the public, that may have informed the final decision of the IAA. The second main objection was that what was sought in substance was a mandatory order, and that the airlines had not reached the threshold for that relief.
25. It is important to note that this application was not merely concerned with a replication of the issues that gave rise to the November 2024 stay application. While it is true that there was a considerable overlap in the issues and that much of the evidence and arguments made in that application remained material to this application, there are differences. The fresh issues that I consider important include the following:
a. First what was sought was not a stay on an existing decision, instead the application sought to prevent the IAA from taking account of the 32mppa in a decision that has not yet been made. Accordingly, this is better characterised as an application for an injunction rather than a stay.
b. Second, the application was capable of being considered in the light of what actually happened following the inclusion of the 32mppa considerations in the Winter 2024 decision - which had not been the subject of a stay application.
26. For the purposes of this application the parties also prepared an issues paper, which guided the arguments at hearing. I will refer to those issues as the judgment proceeds.
THE EVIDENCE
27. In addition to affidavits that had been filed for the purposes of the November 2024 stay application, the court has considered the following:
a. Affidavit of Eoin Kealy, sworn on behalf of Ryanair on the 19 March 2025
b. Affidavit of Laurence Gourley, sworn on behalf of Aer Lingus on the 26 March 2025
c. Affidavit of Doug Mullen, sworn on behalf of the A4A applicants on the 19 March 2025
d. Affidavit of Aidan Corcoran, sworn on behalf of the IAA on the 21 March 2025
e. Affidavit of Simon Fagan, sworn on behalf of daa on the 26 March 2025
28. All affidavits sworn on behalf of the airline applicants referred back to the matters that they had addressed in their previous affidavits, which included evidence of the basis for their concerns that unless the PATM seat cap element in the S25 decision was stayed they would suffer serious irreparable harm. That harm was a combination of the loss of income due to the reduction in passenger numbers, the consequent effect on the companies from an employment perspective, the potential loss of historic slots, the reduction in or loss of ad hoc slots, and concerns about the potential serious effect of the PATM seat cap on the broader economy. It can be noted that the airlines within the A4A group of applicants addressed additional concerns particular to their circumstances which included their ability to access the market and competition issues.
29. Before setting out the specific concerns and issues raised by the individual deponents it is possible to set out certain contextual matters that were common to the parties and not disputed.
30. The timeline for the forthcoming Winter 2025 coordination parameters decision is as follows:
a. 12 March 2025: the Dublin coordination committee met to discuss the coordination parameters for Winter 2025.
b. 8 April 2025: the IAA is to deliver its draft decision on coordination parameters for Dublin Airport for Winter 2025.
c. 8 May 2025: by that date, the IAA is to deliver its final decision on coordination parameters at Dublin Airport for Winter 2025.
31. While specific dates have not been fixed it can be noted that the likely timeline for the Summer 2026 decision process will involve the following:
a. August 2025: meeting of the coordination committee to discuss the Summer 2026 coordination parameters for Dublin Airport.
b. September 2025: the IAA will deliver its draft decision.
c. Early October 2025: the IAA will deliver its final decision on coordination parameters.
32. For the purposes of the coordination committee meeting on the 12 March 2025, daa provided slides setting out its projections of passenger throughput at Dublin Airport for Winter 2025, and also setting out a number of scenarios in which different potential approaches to the 32mppa conditions could be addressed.
33. In the first instance, daa is projecting that, relative to Summer 2024, there will be an increase of passenger numbers in 2025, up to October 2025, in the amount of 1.55 million. On the figures, daa was projecting that by the start of Winter 2025, relative to start of Winter 2024, passenger numbers will have increased by 1.45 million. This was presented to show that, on daa's figures, simply rolling over the Winter 2024 PATM seat cap would not be sufficient to achieve compliance by daa with the 32mppa conditions. Projections were made by daa in respect of various scenarios for the full year of 2025.
34. Scenario 1 was based on a seat cap applying for November and December 2025. In that scenario, daa worked on the basis that the IAA would impose a seat cap of 2.5 million passengers for November and December 2025. That would result in a total passenger count of 32 million passengers for 2025.
35. Scenario 2 was based on the IAA imposing the same seat cap as Winter 2024, 14.4 million. That would result in a total passenger count of 34.5 million passengers for 2025.
36. Scenario 3 was based on no seat cap being imposed for Winter 2025. That would result in a total passenger count for 2025 of 34.65 million passengers.
The evidence from Ryanair
37. Ryanair noted that in its statement of grounds for the Summer 2025 proceedings, it had sought a declaration in general terms concerning the legality of treating the 32mppa conditions as relevant constraints. That declaration, it was said, was directed to a broader issue concerning the validity of the Summer 2025 decision itself.
38. Ryanair notes that since the November 2024 judgment, daa had made applications to Fingal County Council seeking to address the passenger limits conditions. Those applications have yet to be determined conclusively.
39. Ryanair also notes that, in its view, Dublin Airport is capable of accommodating further growth. This touches on the argument that the Slot Regulations should be approached in a maximalist way, i.e. providing for the greatest number of slots that can be accommodated. In that light, the 32mppa conditions are said to amount to an artificial constraint on growth at the airport.
40. Ryanair addressed the effect of the PATM seat cap which formed part of the Winter 2024 decision. It can be recalled that while the Winter 2024 decision was challenged by way of judicial review, there was no application for a stay on the PATM seat cap element in the decision, and hence the PATM seat cap went ahead and its effects can now be stated with some clarity. Ryanair state that the seat cap had an appreciable effect on its ability to access ad hoc pool slots. Ryanair was allocated approximately 2,600 pool slots in Winter 2023, but in Winter 2024 it was only allocated 183 such slots. Those ad hoc pool slots allow airline operators to provide additional flights to cater for matters such as extra flights at Christmas, St. Patrick's Day, and school holidays, together with flights for sporting events such as the Cheltenham festival and Six Nations rugby matches.
41. Ryanair states that the Winter 2024 seat cap resulted in a loss of 2,610 flights and a consequent loss of revenue of €35.8 million.
42. Ryanair estimates that seat capacity at Dublin Airport for Summer 2025 will be 28,702,810. Applying a projected load capacity of 87%, this would mean that 24,971,444 passengers will pass through the airport. If that is so, and if the PATM seat cap is applied in Winter 2025, it would require the imposition of a seat cap significantly below the Winter 2024 cap of 14.4 million passengers if the 32mppa conditions were not to be breached. Ryanair estimated that a seat cap of approximately 11.3 million passengers for Winter 2025 would be required. As with all the parties, Ryanair based its approach on reasoned estimates flowing from identified premises. However, there was little dispute around the likely effects identified by the airlines, and there was consensus that the imposition of a seat cap would operate to the detriment of the airlines.
43. Ryanair described the projected effects if the likely seat cap was imposed. First, Ryanair contended that it would inevitably lose some 6,800 historic slots, and, as described in the November 2024 judgment, it is likely that the loss of historic slots could not be reversed. Second, there would be a loss of 1.3 million seats with a consequent loss of revenue of €93.4 million.
44. Ryanair commented on the projections that daa shared with the coordination committee. It noted that Scenario 1 would involve an over 50% reduction in passenger throughput for November and December 2025 with consequent serious effects for the travelling public over the Christmas period and effects on the national economy.
45. If the seat cap estimates of 25 million passengers for Summer 2026 season were applied, Ryanair estimated that there would be loss of 1,580,000 seats with a consequent loss of 8,300 historic slots and €113,500,000 in revenue. With a projected seat cap of 25.2 million passengers for the same seasons, there would be a loss of 7,900 historic slots and €108,200,000 in revenue. If the seat caps were imposed for successive seasons until the determination of the questions referred to the CJEU and the determination of these proceedings, Ryanair would suffer continuing serious and irremediable losses.
46. Outside of the effects on the airline, Ryanair noted that the imposition of the seat cap would damage the national economy, inconvenience millions of passengers and their families, and result in significant price rises for consumers during periods of high demand.
47. Ryanair make the point that it would be pragmatic and sensible to deal with the injunction application pending the determination of the proceedings as the alternative would involve twice yearly fresh judicial review proceedings (challenging each seasonal PATM seat cap decision) and likely stay applications shortly thereafter. This would amount to a highly expensive and wasteful use of resources.
The evidence from Aer Lingus
48. The evidence adduced by Aer Lingus addressed the effects of a seat cap on that airline in Winter 2025 and subsequent seasons. In common with the other airlines, it noted the various scenarios that daa had placed before the coordination committee and expressed concerns about the implications of implementing a PATM seat cap.
49. In relation to Scenario 1 - involving a seat cap specific to November and December 2025 in the amount of 2.5 million passengers - Aer Lingus noted that this amounted to a 50% reduction in seats for that period compared to the equivalent period in 2024. This reduction was described as "drastic", and Aer Lingus estimated that it would result in a loss of historic slots, a reduction of 825,000 seats and a revenue loss of €85 million.
50. Aer Lingus also described the broader effects of Scenario 1 as including a substantial drop in revenue for Dublin Airport, serious impacts on the air travel industry as well as for the retail, hospitality and tourism sectors. There would also be a reduction in available flights for the general public, higher ticket prices and inconvenience - particularly over the Christmas holiday period.
51. Scenario 2 - which involved the imposition of the same PATM seat cap as in Winter 2024 - would not prevent a breach of the 32mppa limit. Aer Lingus did not consider that Scenario 2 would lead to it losing historic slots, but it would lose some pool slots, and would also need to cancel certain short haul services in order to free up pool slots for some of its long haul services. It estimated losses in the region of €10-€15 million if Scenario 2 was implemented.
The A4A evidence
52. The evidence from these airlines noted that because of the stay on the Summer 2025 seat cap and the fact that the 32mppa conditions apply for each year, it was likely that the IAA would have to impose more serious seat limitations for Winter 2025 than it did for Winter 2024. If that were to occur, the airlines in the A4A group were likely to suffer a loss of revenue, a loss of market share (this was discussed in the previous judgment and relates to the ability of the domestic airlines to adjust their schedules compared to the A4A airlines who cannot employ the same level of flexibility), operational consequences, reputational damage and irreversible loss of historic slots.
53. The airlines in the A4A group note that largely they are relatively new entrants to the market in Ireland, and even if the seat cap for Winter 2025 remained at the same level as that for Winter 2024 (which itself is unlikely) they would not be able to expand services or obtain new slots. The evidence noted that the predictions that had been made in earlier affidavits about the effects on the airlines of the Winter 2024 seat cap had largely proved accurate, and JetBlue was refused slots that had been requested for Winter 2024 which affected its options as a new market entrant.
The evidence from the IAA
54. The IAA evidence started from the premise that its position on the substantive issues remained unchanged: the IAA considered that the 32mppa conditions were a relevant constraint for the purposes of article 6 of the Slot Regulation and therefore the IAA was obliged to take account of those conditions when setting coordination parameters. Entirely without prejudice to that overarching point, the IAA adopted a neutral approach to the relief sought by the airlines.
55. It must be recorded that similar to the position that obtained in connection with the hearings leading to the November 2024 judgment, the IAA approached matters in a fair and candid manner and provided the court with balanced and helpful evidence and submissions. That is not to be treated as any suggestion that any other parties adopted a different approach, all parties endeavoured to be fair and helpful while robustly defending their own perspectives. I highlight the approach of the IAA because (a) it was genuinely helpful, and (b) it is an excellent example of how a public authority respondent in judicial review proceedings should conduct itself.
56. The IAA emphasised that it had not made a decision on the Winter 2025 coordination parameters, but that it proposed to follow its normal process. Among other matters, that would involve taking account of the advice of the coordination committee, considering the relevant facts, and then issuing a draft decision. Following the publication of the draft decision, it would then take account of any submissions that were made before reaching a final binding decision. The IAA was very clear that it could not fetter its discretion. However, it did note that it was reasonable to assume that, acting as a rational decision maker and subject to any new evidence or submissions, the IAA would adopt an approach that was consistent with its earlier decisions.
57. The IAA clarified that there were no issues with it determining the coordination parameters for Winter 2025 (or subsequent seasons) without taking account of the 32mppa conditions. In fact, and again without prejudice to its position on the substantive issues, the IAA expressed the view that there was considerable merit in seeking to avoid further sets of proceedings arising from the same issues in respect of each season pending the determination of the proceedings. That, in turn, would avoid repeated urgent stay or injunction applications being made to the court. Aside from the desire to avoid unnecessary proceedings with the associated costs and impact on court resources, the IAA believed that if the application was granted it would provide a degree of certainty and allow for a more meaningful and informed consultation to take place in relation to the proposed coordination parameters.
58. The IAA addressed the various scenarios that had been put to the coordination committee by daa. In respect of Scenario 1 - where the passenger numbers for November and December 2025 would be halved - the IAA noted the following. First, to prevent 2.65 million passengers using the airport in November and December 2025 it would be necessary to cancel the flights of more than 2.65 million passengers. This was because in response to that level of capacity reduction the load factors on the remaining flights would approach 100% (with a consequent surge in prices). To address that position, it would in fact be necessary to withdraw approximately 3.5 million seats out of the approximately 6 million scheduled seats over November and December.
59. Because of that factor - the need to set a seat cap sufficiently low to prevent the reallocation of approximately 60% of winter slot series/seats - the IAA considered that the airlines' evidence underestimated the negative effects of Scenario 1.
60. In relation to Scenario 2 - the same seat cap for Winter 2025 as in Winter 2024 - again there was a concern that load factors would place downward pressure on the estimate of 14.4 million seats. The IAA considered that if Winter 2025 was approached in the same way as Winter 2024, it would require a seat cap of approximately 13.8 million seats. In turn that would result in a reduction of around 4% of historic slots. However, there would still be a likely breach of the 32mppa conditions.
61. The IAA position was that, if the application was granted, the coordination parameters for Winter 2025 and subsequent seasons would permit the full allocation of historic slots and associated seats as well as the facilitation of demand for new routes and new operations. It would also mean that ad hoc pool slots could be allocated so that the airport could be used scalably for peak demand periods, such as Christmas and in response to events such as sporting events being held in Ireland.
62. The IAA was of the view that the proposed order would not affect the coordination committee and public consultation processes. In that respect, the IAA noted the value in certainty: the processes would benefit from the clarity of knowing whether the 32mppa conditions were applicable or not. That was contrasted with a position where the public might approach the consultation process on the basis that the 32mppa conditions were relevant constraints only to see the subsequent decision challenged in a similar manner to the Summer 2025 decision.
63. Finally, the IAA also addressed a suggestion from daa that if the application was to be granted, the terms should be amended to limit the application of the PATM seat cap to "what is necessary to preserve historic slots". This was said by daa to be consistent with the ratio of the November 2024 judgment.
64. That approach was actively opposed by the IAA. First, it was said that it was difficult to see how that amendment could be effected in a way that was consistent with the Slot Regulation. The IAA noted that, under the statutory process, the IAA determines the coordination parameters, after which ACL then makes decisions on the allocation of slots. While the application by the airlines would constrain the IAA in one particular respect in determining coordination parameters, the daa amendment would have the effect, it was said, of leapfrogging the functions of both the IAA and ACL in determining what slots were to be allocated - being only historic slots. Second, from a practical perspective it was not clear how the coordination parameters could be set to take account of the 32mppa conditions in a way that would allow ACL to reallocate all historic slot series in full.
The evidence from daa
65. daa opposed the relief being sought by the airlines. Its view was that, in effect, what was being sought would impact on the coordination committee process and impinge on the rights of the public to engage in consultation. Instead, daa advocated for allowing the statutory process to play itself out to the point where a decision was made by the IAA at which point it would still be open to a party to review that decision and if required to apply for interlocutory relief.
66. daa also identified certain new factual matters that were said to be relevant. There was a description of engagements with Fingal County Council, and it was noted that on the 17 December 2024 the council sent a fourth warning letter concerning alleged breaches of the 32mppa conditions. daa responded to the warning letter with its own lengthy letter of reply dated the 23 January 2025. That letter noted, among other matters, that insofar as there was any breach of the 32mppa this was due to circumstances entirely outside the control of daa. As of the date of the swearing of the daa affidavit, the council had not responded to the daa letter from the 23 January 2025.
67. Next, daa explained that it had made further applications to amend the 32mppa conditions. On the 15 December 2023, daa had applied to Fingal County Council to increase passenger numbers to 40mppa together with certain infrastructural investments. That prompted requests for further information from Fingal County Council and the Aircraft Noise Competent Authority (ANCA). Separately, daa lodged an application on the 20 December 2024 which was restricted simply to seeking an increase in passenger numbers, with no application for infrastructural works. That application was treated as invalid by Fingal County Council, and a second similar application was submitted on the 6 February 2025. A public consultation process was undertaken, which closed on the 12 March 2025. In addition, ANCA determined that a noise assessment was required for that application, a proposition with which daa disagreed. Whether or not the various applications are decided prior to the determination of the reference to the CJEU, it is likely to take some time.
68. Third, daa explained its views on likely passenger number growth at the airport. daa noted that in 2024 the passenger count reached 33,151,102, thus exceeding the 32mppa. The projections for 2025 suggest that without measures being taken for the Winter 2025 season, numbers will exceed the 32mppa. Similar, albeit more rough, estimates for 2026 suggest further breaches. In effect, and this does not appear to be disputed, daa confirms that if the relief sought is granted there would be a series of increasing breaches of the 32mppa.
69. In addition, daa suggest that over and above protecting the existing entitlements of the airlines, one of the practical effects of permitting the increasing growth in seat numbers would be that the airlines would accrue new entitlements to historic slots.
70. daa disagree with the Ryanair assertion that the capacity of Dublin Airport is 40 million passengers. In that regard, daa exhibited a report from Ricondo (aviation consultants) which found that baseline airport capacity for all passenger categories is 36.5mppa.
71. Ultimately the daa deponent asserted that a variety of different scenarios could be proposed and adopted for the Winter 2025 season, and that the IAA and interested parties should be permitted to consider those different scenarios on a season by season basis based on the circumstances prevailing at the time.
72. Finally, daa addresses its proposal that if the application is to be granted the relief should be framed in such a way as to restrict itself to protecting existing historic slots. daa disagrees that this would interfere with the statutory processes any more than the existing formulation of the relief.
THE PRINCIPLES APPLIED BY THE COURT IN THIS APPLICATION
Jurisdiction
73. In the first instance, the court is satisfied that it has jurisdiction to make the orders sought. Order 84, rule 20(8) RSC provides:
"Where leave to apply for judicial review is granted then the Court, should it consider it just and convenient to do so, may, on such terms as it thinks fit:
(a) grant such interim relief as could be granted in an action begun by plenary summons,
(b) where the relief sought is an order of prohibition or certiorari, make an order staying the proceedings, order or decision to which the application relates until the determination of the application for judicial review or until the Court otherwise orders."
74. The case law is clear that the distinction in Order 84, rule 20(8) RSC between a stay and an injunction is not based on the fact that different criteria should be applied to the grant of those relief but rather because there is a difference in substance between a stay and an injunction. A stay is applicable to a situation where the legal effect of a legally binding measure is suspended, while an injunction applies where it is necessary to put in place a regime, pending trial, to protect the interests of the parties. However the relief is characterised, the criteria for the grant of an injunction involves the application of the same criteria that apply to the grant of a private law injunction; see in that regard Okunade v. Minister for Justice [2012] 3 IR 152, and the cases referred to in that judgment.
75. Hence, while this is an application for an injunction and not a stay, I am satisfied the criteria to be applied are the same criteria that were explained and applied in the November 2024 judgment.
76. There is a further point applicable to injunction applications, which is that, as a matter of general principle, interlocutory relief should be ancillary to a substantive relief that has been sought in the underlying proceedings. In that regard, it is important for this application that while the Summer 2025 judicial review proceedings responded to and sought to quash the specific decision that involved the PATM seat cap for Summer 2025, broader declaratory relief was sought. While all the airlines have sought declarations, the Ryanair proceedings seek the following, which is illustrative of the proposition:
"5. A Declaration by way of Judicial Review that the IAA is not and was not entitled to have regard to planning conditions and in particular [the 32mppa conditions] when determining parameters for slot allocation at Dublin Airport in accordance with Council Regulation (EEC) No. 95/93 of 18 January 1993 on common rules for the allocation of slots at Community airports, as amended ('the Slot Regulation')".
77. From the manner in which the relief is framed - "is not and was not entitled" - it is clear that that relief is not directed to the circumstances of the specific decision challenged elsewhere in the proceedings, but instead is directed to the broader legal position.
78. The court is satisfied that this relief provides the requisite foundation for an application for injunctive relief directed to future decisions in which there is a reasonable apprehension that the IAA will continue to have regard to the 32mppa conditions as relevant constraints for article 6 purposes. The Supreme Court has made clear, inter alia, in PMcD v. The Governor of X Prison [2022] 1 IR 741 that in the appropriate circumstances a declaration can be granted as a standalone relief; and there is extensive authority that where a court grants a declaration as to the vires of a public body, ordinarily it should not be necessary to make an order of mandamus compelling the public body to act in the way set out in the declaration. Finally, it can be noted that when the time comes for the determination of the Summer 2025 proceedings there is every likelihood that the immediate impugned decision will be spent. The presence of an application for a declaration that addresses the overall or broader relationship between the 32mppa conditions and the article 6 functions of the IAA will operate to rebut any potential argument that the proceedings have been rendered moot, and will ensure that this critically important systemic issue can be determined.
The type of injunction sought
79. The parties disagreed about whether the relief sought was mandatory - the position adopted by daa - or prohibitive - the position adopted by the other parties. The distinction is material because different tests apply to each form of injunction, with the applicants being required to establish a strong case that they were likely to succeed in their actions if a mandatory injunction was to be granted (Maha Lingam v. Health Service Executive [2005] IESC 89). It is to be recalled that the order sought is one that seeks to prevent the IAA from taking account of the 32mppa conditions for the purposes of setting coordination parameters.
80. daa argues that, despite the manner in which the relief is framed, in substance what has been sought is mandatory. This is because, in reality, it involves the court directing in a mandatory sense how the IAA will go about the task of setting coordination parameters.
81. The case law makes clear that what renders an interlocutory injunction mandatory depends on the substance of the relief sought rather than the phraseology used. This is because, as put by Murray J. in Ryanair v. Skyscanner Limited & Ors [2022] IECA 64, at para. 33(ii), "[a]ny positive assertion can be expressed as a negative". In that case Ryanair was found to have sought orders that required the defendant to monitor and control the behaviour of a third party by either changing its terms of dealing with online travel agents or enforcing existing terms agreed with those undertakings. The Court of Appeal stated that the court must focus on what the injunction actually requires the defendant to do.
82. daa also relied on the judgment of Ní Raifeartaigh J. in Fitzpatrick v. Minister for Agriculture, Food and the Marine [2018] IEHC 77. In that case there was no dispute that the interlocutory injunction sought in those judicial review proceedings was mandatory in nature. The application arose after the Minister closed a fishing area to fishing for Dublin Bay Prawns. That decision was made on foot of information from the Sea Fisheries Protection Authority (SFPA) that the quota had been exceeded. The dispute related to the manner in which the relevant catches were calculated. The applicants argued that catches should be calculated according to what was recorded in each fishing vessel's logbook. The respondents sought to employ other methods due to their belief that the logbooks under recorded catches. In addition to seeking orders restraining the Minster from relying on the SFPA methodology, the applicants sought an injunction "requiring the Minster to reopen or make a quota allocation ... based on the data for ... catch as disclosed in the fishing logbooks". Interlocutory orders were also sought against the SFPA "requiring the [SFPA] to base its report to the European Commission ... on the data contained in the fishing logbooks". It is apparent that the orders were strongly opposed by the parties against whom the orders were sought.
83. The High Court in Fitzpatrick, at para. 65, while expressing that the issue was somewhat finely balanced, found on balance that the relief sought was mandatory in nature "because it sought to compel the State authorities to carry out their legal obligations (into the future and pending the determination of these proceedings) in a very particular and precise way, namely to gather and transmit and based (sic) decisions upon a particular method, or groups of methods, of collecting information in relation to, and calculating, prawn catch figures."
84. In my view, the orders sought and ultimately refused in Fitzpatrick went considerably further in terms of their nature and effect than the orders sought in this application, and this is a significant point of distinction. In this application, the IAA agrees that it will be able to carry out its statutory functions in a logical and regular manner if it is restrained from taking account of certain specific factors. The situation in Fitzpatrick was different. There the court was asked to direct the respondents to carry out its function of calculating catch in a detailed and prescriptive manner and in a way that the respondents argued amounted to a significant intrusion on its functions. In those premises, I do not consider that the Fitzpatrick case provides a useful authority for the position agitated for by daa. If anything, Fitzpatrick suggests that there are real issues with the alternative wording proposed by daa, which it seems to me is much closer to a mandatory order as it would require the IAA and ACL to do something very specific: to maintain historic slots at their current level.
85. Considering the terms of the orders sought in this application, I am satisfied that what has been sought in substance is an injunction that simply restrains the IAA from taking account of one factor among many that will have to be considered. At one level, as with a lot of injunctions, the effect of the order will be that the IAA will have to carry out its statutory functions in a particular way and in a way that would not have obtained if there was no injunction. However, it must be borne in mind that the IAA in any event is required to carry out the function of determining coordination parameters. That obligation stems from the Slot Regulation and not from any order of the court. The effect of the injunction is not that the IAA must do something. Instead, the orders sought temporarily removes one of those factors from the equation.
DISCUSSION: THE INJUNCTION SOUGHT
86. The question then is whether the ordinary test for an interlocutory injunction has been met. I have set out what I consider to be the relevant principles in the November 2024 judgment. Here, I consider that the logic of the November 2024 judgment requires that the injunction should be granted unless any change in circumstances warrants such a departure.
87. The argument pressed by daa was that a significant difference between the current application and the situation that presented itself in November 2024 is that what is proposed is the court intervening in a statutory process that has not had the opportunity to reach its own conclusion.
88. daa points to authorities which they say have the effect of requiring the court to refuse the application. It was accepted that, if adopted, the course of action proposed by daa would almost inevitably lead to a further judicial review applications and applications for stays.
89. The starting point for this element in the argument is the decision fo the Supreme Court in Tormey v Ireland [1985] I.R. 289. There, the plaintiff had been sent forward to trial in the Circuit Criminal Court but sought to have his trial transferred to the Central Criminal Court on the argument that pursuant to Article 34 of the Constitution the High Court enjoyed full original jurisdiction. In those premises the plaintiff, inter alia, challenged the constitutionality of section 32(1) of Courts Act, 1981 on the basis that it removed an earlier statutory provision that had allowed for the transfer of trials from the Circuit Criminal Court to the Central Criminal Court. The claim was dismissed by the High Court. In the Supreme Court, Henchy J. analysed the relevant provisions of the Constitution and held that the "full" original jurisdiction of the High Court must refer to all justiciable matters and questions. In that light, where a matter has been devolved on an exclusive basis to the District or Circuit Court, the "full jurisdiction is there to be invoked - in proceedings such as habeas corpus, certiorari, prohibition, mandamus, quo warranto, injunction or declaratory action - so as to ensure that the hearing and determination will be in accordance with law."
90. Tormey was considered by the Supreme Court in Criminal Assets Bureau v. Hunt [2003] 2 IR 168. There the Court found that the logic of Tormey as it applied to the District and Circuit courts extended to other tribunals exercising "limited functions and powers of a judicial nature", within the terms of Article 37.1 of the Constitution.
91. The line of authority was further considered in Grianán an Aileach Interpretative Centre Company Limited v. Donegal County Council [2004] 2 IR 625. Grianán concerned a question around consent that had been sought for a schedule of activities in an interpretative centre that was subject to an existing planning permission. One of the conditions attached the permission was that use was restricted to the matters indicated on plans submitted with the application, and "for no other use without the prior written agreement of the planning authority". The plaintiff sought the council's permission for a series of events, and the council indicated that the activities included matters that were not envisaged by the permission. The council had indicated that enforcement proceedings may be brought if the non-permitted activities persisted, but such proceedings had not actually been brought.
92. The plaintiff issued plenary proceedings effectively seeking declarations that the contested activities were uses permitted by the permission, and then issued a motion seeking to enjoin the council from taking steps to prevent the contested uses. The High Court formulated a declaration that declared the types of uses that could be carried out on the premises, reflecting what the court considered to be the "true meaning of the planning permission".
93. The Supreme Court considered that the issue in the case focussed on whether the proposed uses were authorised, but that this required the deciding body to determine if what is being proposed constituted a material change of use. That meant that the fundamental issue was whether the proposed uses constituted "development", which was a matter entrusted to the planning authority and An Bord Pleanála by section 5 of the Local Government (Planning and Development) Act, 2000.
94. In Grianán, Keane C.J., relying on the line of authority from Tormey, explained that while the High Court could be called upon to determine whether there had been a material change of use if an enforcement notice had issued and was challenged, the High Court should not determine the issue "as though it were the planning authority" as that would give rise to the risk of overlapping and unworkable jurisdictions arising. That is a critical distinction with the present case. As I understand it, the concern in Grianán was that the remedy - the particular form of declaration made - went beyond any requirement to interpret a particular provision or document to decide if a specific use was permitted, and moved the court into a role analogous to that of a planning authority granting a permission.
95. In the premises, I do not see the Tormey line of authority as applicable in this situation. The High Court is seised with judicial review proceedings where the point of the actions is to determine whether or not the decisions of the IAA to take account of the 32mppa conditions were in accordance with law. That is a discrete, if potentially difficult, question of law, the interpretation of which ultimately is a matter for the court. In that specific context, an injunction has been sought to temporarily remove a specific factor - which directly relates to the issue in the main proceedings - from the consideration of the IAA pending the determination of those proceedings. This is not a situation where the High Court is stepping into the shoes of the decision maker identified by legislation. Save in that one limited respect (albeit an important respect) the IAA is free to discharge its functions to determine coordination parameters as it considers fit. The intervention of this court is limited to that specific matter, which itself is the subject of current court proceedings.
96. In many respects, while the situations are not perfectly analogous, there is a similarity between what has been sought here and the situation that arose in Pesca Valentia v. Minister for Fisheries [1985] IR 193 (the judgment in that case, as it happens, being delivered a number of days after the judgment in Tormey). There the Supreme Court upheld an interlocutory injunction granted by the High Court that restrained the Minster from enforcing a condition attached to licences which mandated that boats should not be used for sea fishing unless 75% of the crew members were Irish or EEC citizens. The conditions were imposed by a statutory provision inserted by s.2 of the Fisheries (Amendment) Act, 1983. Hence, questions of the constitutional presumption of validity were in play and the orders as noted by Finlay C.J. had the consequence of "preventing the Executive from carrying out powers vested in them by a Statute enjoying that presumption". Those were significant matters to be considered in weighing the balance of convenience, but they did not give rise to the application of "any special principle applicable to an application for an interlocutory injunction of this kind".
97. I have concluded that the proposed order does not involve the court stepping into the shoes of the IAA or otherwise carrying out a function that is analogous to the function that the IAA will have to discharge in setting the coordination parameters.
98. daa make the further argument that the decision-making process should be allowed to follow its ordinary course and that once a decision is made by the IAA the parties can then decide on the appropriate response.
99. I accept as a general proposition that there are benefits in allowing a process such as the determination of coordination parameters to follow the prescribed statutory course before an intervention is contemplated. daa correctly observed that not only does this show respect to the statutory process and permits the usual process of consultation to proceed, but also that it means that the court hearing an application for a stay on a decision is better equipped to carry out an adjudication because a greater level of more precise information will be available. However, those propositions must be tested against the backdrop of the existing evidence.
100. In that respect, it is clear (or as clear as can be) that the overwhelming likelihood is that the IAA will take account of the 32mppa conditions in setting the coordination parameters and that this will lead to precisely the same issues (albeit with different figures for likely loss) that led to the November 2024 application and judgment.
101. Because it is not permitted to fetter its discretion, the IAA very properly refused to indicate in advance what decision it was likely to make. However, that does not prevent the court having regard to the fact that for the purposes of the underlying proceedings the IAA remains of the strong view that it is required to take account of the 32mppa conditions. When that is combined with the IAA evidence that (a) it intends to follow its usual process, and (b) that it recognises the value of consistency in those processes, I am prepared to find that unless restrained by the court the IAA will take account of the 32mppa conditions.
102. I accept the arguments made by the IAA that the process is best served by having a degree of clarity brought to proceedings. While it is true that members of the public or members of the coordination committee may wish to make submissions about whether or how the 32mppa conditions should form part of the considerations of the IAA, the reality is that that is a question of law. The IAA either is entitled to have regard to the 32mppa conditions or it is not. The IAA has formed a clear legal view on that question, so submissions supporting that proposition would seem unnecessary. Likewise, given what has transpired to date, it is unlikely that a submission to the effect that the 32mppa should not be taken into account will have the effect of changing the mind of the IAA.
103. In those premises, it seems somewhat redundant to have to wait for that outcome, wait for inevitable sets of judicial review proceedings to issue, and then address an equally inevitable application or number of applications for stays on the decision on Winter 2025 parameters. I do not consider that there is any merit in taking a course that inevitably subjects the parties to further significant expense or to the further diversion of scarce court resources, when that can be avoided, and where a proper adjudication can occur at this point.
104. In terms of how the balance of justice should be addressed, it seems to me that all of the factors that applied in the November 2024 judgment remain live in this application, save that as noted above in the section of this judgment dealing with evidence, the precise estimates for the harm to the airlines necessarily must be adjusted. Nevertheless, the position remains that unless the IAA is restrained pending the determination of these proceedings from taking account of the 32mppa conditions and imposing PATM seat caps, it is clear that the applicant airlines will suffer serious irreparable harm. As noted in the November 2024 judgment, that harm is not restricted to the loss of historic slots (as important as that matter is) but includes the loss of access to allocations of ad hoc pool slots and serious financial harm that likely cannot attract compensation. I am not satisfied that any of the new matters referred to by daa have the effect of altering my analysis of the balance of justice as set out in the November 2024 judgment. I will rehearse that analysis in this judgment as the issue was addressed comprehensively in my earlier judgment and I am satisfied that mutatis mutandis the situation is essentially the same.
105. Finally, I am not satisfied that the amendments proposed by daa to the orders sought by the airlines in this application should be granted. I have reached that view for two main reasons.
106. First, the amendment is predicated on the proposition that the ratio of the November 2024 judgment was that the loss of historic slots outweighed the competing considerations relied on by daa. It is correct that the loss of historic slots was and remains a substantial and weighty consideration. However, there was a number of other factors that combined to outweigh the considerations identified by daa, not the least of which was the very significant irreparable financial harm that the airlines will suffer if the PATM seat cap is maintained. The evidence in this application establishes that for the Winter 2024 decision - where there was no stay on the PATM seat cap element - the airlines have suffered serious financial harm. It bears reiterating that this is a situation where the consensus view is that it is likely that if the airlines succeeded in the underlying proceedings there will be no available remedy in damages.
107. Second, as I mention above, the proposed amendment in fact comes very close to tipping the substance of the order into one more resembling a mandatory order. Moreover, the proposal in my view also comes closer to the type of order deprecated in the Tormey line of authority. The IAA are strongly opposed to the amendment proposed by daa. That in itself is a weighty consideration, as the IAA will be the party required to comply with any order. The IAA has suggested that it is very hard to see how preserving historic slots can be achieved in the way proposed. The IAA say that allocating or accommodating historic slots is a feature of the function carried out by ACL in allocating slots, which occurs after the IAA has determined the coordination parameters. On that basis, the IAA observe, with considerable merit in my view, that what is proposed by daa, even if workable, amounts to a greater interference with the statutory process than what has been sought by the airlines.
CONCLUSION
108. In the premises, I intend to grant an interlocutory injunction pursuant to Order 84, rule 20(8)(b) of the Rules of the Superior Courts in the terms sought by the airlines. That order will remain in place pending the determination of these proceedings by the High Court. I will provide that the parties will have liberty to apply to amend vary or discharge that order on 72 hours' notice in the event of any material change in circumstances.
109. This judgment is being delivered electronically, so I will list the matter for mention before me at 10.30 on Thursday, the 3 April 2025 for any submissions that may be required on the final form of orders and costs. I would invite the parties to liaise in that regard.