APPEAL COURT, HIGH COURT OF JUSTICIARY
 HCJAC 28
OPINION OF THE COURT
delivered by LORD EASSIE
APPEAL AGAINST SENTENCE
DAVID NICOL CAMPBELL
HER MAJESTY’S ADVOCATE
Appellant: C Fyffe, Solicitor Advocate; Paterson Bell Limited (for Bruce Short & Co, Dundee)
Respondent: Farquharson, AD; Crown Agent
14 January 2015
 On 31 July 2008 the appellant was convicted in the Crown Court in Carlisle of a charge of robbery in terms of section 8 of the Theft Act 1968. He was sentenced by the Crown Court to a term of imprisonment of eight years. After he had begun serving that sentence he was transferred to a prison in Scotland on an “unrestricted” basis in terms of Schedule 1 to the Crime Sentences Act 1997 as applied by section 41 of the Act. He was later released at a point which accorded with the early release provisions set out in Part 1 of the Prisoners and Criminal Proceedings (Scotland) Act 1993, namely on 29 November 2013.
 On 20 June 2014 at a sitting of the High Court of Justiciary in Livingston the appellant pled guilty to a number of offences committed in Scotland subsequent to his release from the sentence imposed by the Crown Court in England. The sentencing judge imposed terms of imprisonment on all of the charges, including as respects a group of three charges a cumulo extended sentence of nine years of which the custodial part was four years and six months. However, in addition, the sentencing judge pronounced an order under section 16(2) of the Prisoners and Criminal Proceedings (Scotland) Act 1993 -“the 1993 Act”– that the appellant be returned to prison to serve 600 days of the sentence imposed by the Crown Court in England on 31 July 2008. The sentencing judge ordered that the period of 600 days be served prior to the sentences imposed in respect of the offences which were before the sentencing judge in Livingston. In this appeal against sentence, the principal point taken is whether it was within the competence or jurisdiction of the sentencing judge to make an order under section 16 of the 1993 Act in respect of a sentence imposed by a court in England and Wales.
 As, we think, became increasingly appreciated in the course of the hearing of this appeal before us, constituted as a two judge quorum, the issue is one which might more properly be considered by a bench of three judges. Having given further consideration to the submissions advanced and the various statutory provisions in issue (which includes an element of legislative archaeology) we have both come to the clear view that the issues present no obvious or unarguable answer and thus call for consideration by a larger bench.
 However, it may of some assistance for that future consideration if we set out something of the legislative history and endeavour to point to what appeared to us to be some relevant considerations affecting the competency point raised by the appeal.
Early release – England and Wales
 In 1988 there was published the report of a review committee chaired by Lord Carlisle of Bucklow QC on “The Parole System in England and Wales” (1988 Cmd. 532). In light of its recommendations, Parliament enacted Part II of the Criminal Justice Act 1991 – “CJA91”– dealing with the early release of prisoners. In brief summary, section 33 of the CJA91 introduced the concept of short and long term prisoners, the former being those sentenced to a term of less than four years in prison and the latter being those sentenced to four years or more. The category of short term prisoners was subdivided into those who had been sentenced to a term of less than 12 months and those who had been sentenced to a term of 12 months or more (but less than four years). The Secretary of State was required to release those in the first subcategory unconditionally once the prisoner had served one half of the sentence; a prisoner in the second category required to be released when he or she had served one half of the term, but in that case the release was to be on licence. A long term prisoner required to be released on licence once the prisoner had served two thirds of the sentence; but he or she might be released, on recommendation of the Parole Board, once one half of the term had been served. There are various qualifications to that basic structure in Part II of the CJA91 but it is, we think, unnecessary to detail them.
 Return to prison following conviction for a new offence during the currency of the term imposed for the original offence was treated principally in section 40 of the CJA91. Subsection 2 of that section provided:
“(2) Subject to subsection (3) below, the court by or before which a person to whom this section applies is convicted of the new offence may, whether or not it passes any other sentence on him, order him to be returned to prison for the whole or any part of the period which –
(a) begins with the date of the order; and
(b) is equal in length to the period between the date on which the new offence was committed and the date mentioned in subsection (1) above [the date upon which, but for his release, the prisoner would have served his sentence in full].”
The qualification made in subsection (3) was that the power of a magistrates’ court to order return was restricted to a period of six months; but a magistrates’ court might commit the prisoner, on bail or in custody, to the Crown Court for sentence in accordance with section 42 of the Powers of Criminal Courts Act 1973. There are various other provisions within Part II CJA91 respecting life prisoners, young offenders, and persons extradited to the United Kingdom which, again, we think unnecessary to detail.
 More importantly for present purposes, none of the provisions of Part II CJA91 apply to Scotland or Northern Ireland – see CJA91, section 102. No power or jurisdiction was given to a court in Scotland or Northern Ireland to order a person who had previously been convicted in England and Wales and who, while on early release, committed an offence in those jurisdictions to be returned to prison to serve any part of the unexpired portion of the original English sentence.
 The provisions of Part II of the CJA91 have been largely replaced by the provisions in Part V of the Criminal Courts (Sentencing) Act 2000. We think it sufficient to say that as respects the power of a court in England and Wales to order a return to prison, section 116 of that Act appears to us to re‑enact grosso modo the earlier equivalent provisions of the CJA91, principally section 40. Again these provisions only apply to a court in England and Wales. No court outwith England and Wales which convicts a prisoner released from an English sentence is given any power to make any order in respect of that English sentence.
Early release – Scotland
 The review chaired by Lord Carlisle in England and Wales was matched, albeit somewhat later, by the Kincraig report on “Parole and Related Issues in Scotland” (1989 Cmd.598). Its recommendations form a background to the 1993 Act. As is well appreciated by those engaged in the criminal courts in Scotland, the 1993 Act adopted the basic approach of Carlisle and the CJA91. It made the same distinction between short term and long term prisoners; and it adopted the notions of early release unconditionally or on licence. But re‑offending while on early release was dealt with slightly differently.
 The leading section of the 1993 Act dealing with the commission of a new offence by a released prisoner prior to the expiry of the full term of his sentence is, of course, section 16. As enacted the relevant text provided:
“16 - Commission of offence by released prisoner.
(1) This section applies to a short-term or long-term prisoner sentenced to a term of imprisonment (in this section referred to as ‘the original sentence’) by a court in Scotland and released under this Part of this Act or Part II of the Criminal Justice Act 1991 if—
(a) before the date on which he would (but for his release) have served his sentence in full, he commits an offence punishable with imprisonment (other than an offence in respect of which imprisonment for life is mandatory); and
(b) whether before or after that date, he pleads guilty to or is found guilty of that offence (in this section referred to as “the new offence”) in a court in Scotland or England and Wales.
(2) Where the court mentioned in subsection (1)(b) above is in Scotland it may, instead of or in addition to making any other order in respect of the plea or finding—
(a) in a case other than that mentioned in paragraph (b) below, order the person to be returned to prison for the whole or any part of the period which—
(i) begins with the date of the order for his return; and
(ii) is equal in length to the period between the date on which the new offence was committed and the date mentioned in subsection (1)(a) above; and
(b) in a case where that court is inferior to the court which imposed the sentence mentioned in the said subsection (1)(a), refer the case to the superior court in question; and a court to which a case is so referred may make such order with regard to it as is mentioned in paragraph (a) above.
(3)Where the court mentioned in subsection (1)(b) above is in England and Wales it may, instead of or in addition to making any other order in respect of the plea or finding, refer the case to the court which imposed the original sentence and shall, if it does so, send to that court such particulars of that case as may be relevant.
(4) The court to which a case is referred under subsection (3) above may make such an order as is mentioned in subsection (2)(a) above in respect of the person.
(5) The period for which a person to whom this section applies is ordered under subsection (2) or (4) above to be returned to prison—
(a) shall be taken to be a sentence of imprisonment for the purposes of this Act and of any appeal; and
(b) shall, as the court making that order may direct, either be served before and be followed by, or be served concurrently with, any sentence of imprisonment imposed for the new offence (being in either case disregarded in determining the appropriate length of that sentence).
(6) In exercising its powers under [section 118(4) or 189(1) and (2)] of the 1975 Act, the court hearing an appeal against an order under subsection (2) or (4) above may, if it thinks fit and notwithstanding subsection (2)(a), substitute for the period specified in the order a period not exceeding the period between the date on which the person was released and the date mentioned in subsection (1)(a) above.
 As was pointed out in the submissions to us, it is to be noted that in terms of subsection (1) of section 16 of the 1993 Act a condition for the application of the section is that the prisoner concerned had been sentenced, for the “original offence”, by a court in Scotland. It is also to be noted that, in many respects complementing that provision, subsection 2(b) requires the court convicting of the “new offence” to refer the case to the court convicting of the “original offence” if the former is inferior to the latter. Since the notions of superiority and inferiority imply a hierarchy within a single legal system of courts, it is difficult to see how the section can operate across borders.
 Also of note are the provisions of subsection (3) of section 16. The legislature did not give jurisdiction or competence to a court in England and Wales to make an order requiring the prisoner to return to prison to serve all or any part of the sentence remaining period of the sentence imposed by a Scottish court. It merely enabled a court in England and Wales to refer the matter back to the court in Scotland which had imposed the original sentence.
 Leaving aside for the moment any issues arising from a transfer of sentence, it appears to us that the provisions enacted by the legislature respect the constitutional independence of the legal systems of the constituent parts of the United Kingdom. In the case of a person who, having been convicted in Scotland and while on early release from the sentence imposed by the Scottish court, commits an offence in either England and Wales or in Northern Ireland, no power is given to the court in either of those jurisdictions to intervene in the execution of the sentence imposed by the Scottish court by ordering that the prisoner be returned to prison. The only power given to a court in England and Wales (but not Northern Ireland) is to refer the matter to the original Scottish court. In the case of a prisoner convicted in England and Wales who, following early release, offends in Scotland, no power is given to the Scottish courts to refer the matter to the original sentencing court; let alone a power to intervene in the execution of that original sentence by ordering a return to prison.
Transfer of sentence
 At the time of the enactment of the 1993 Act, and the CJA91 , the legislative provisions respecting transfer of prisoners within the British Isles were contained in Part III of the Criminal Justice Act 1961. The principal section within that part is section 26, which as amended – largely in consequence of the abolition of borstal training- provided:
“26.- Transfer to serve sentence.
(1) The responsible Minister may, on the application of a person serving a sentence of imprisonment or detention in any part of the United Kingdom, make an order for his transfer to another part of the United Kingdom or to any of the Channel Islands or the Isle of Man, there to serve the remainder of his sentence, and for his removal to an appropriate institution there.
(2) Where a person has been sentenced to imprisonment or detention in any of the Channel Islands or the Isle of Man, the Secretary of State may, without application in that behalf, make an order for his transfer to any parts of the United Kingdom, there to serve his sentence of the remainder of his sentence, as the case may be, and for his removal to an appropriate institution in that part of the United Kingdom.
(4) Subject to the following provisions of this section, a person transferred under this section to any part of the United Kingdom or to any of the Channel Islands or the Isle of Man there to serve his sentence or the remainder of his sentence shall be treated for purposes of detention, release, supervision, recall and otherwise as if that sentence (and any other sentence to which he may be subject) had been an equivalent sentence passed by a court in the place to which he is transferred.
(4A) A person who has been sentenced to a sentence of a length which could not have been passed on an offender of his age in the place to which he has been transferred shall be treated for the purposes mentioned in subsection (4) of this section as the Secretary of State may direct.”
Section 32 of the Criminal Justice Act 1961, to which the side note is “Supervision and recall” provided as regards certain enactments, specified in subsection (2) of that section that :
“..in so far as they make provision –
(a) for the supervision of persons released from a prison or other institution in any part of the United Kingdom;
(b) for the imposition upon persons who are released of requirements or conditions to be complied with by them; or
(c) for the recall or return of persons so released to such a prison or institution
shall apply to a person so released who is for the time being in any other part of the United Kingdom or in the Channel Islands or the Isle of Man; and for that purpose those enactments shall extend throughout the United Kingdom, the Channel Islands and the Isle of Man.”
So far as we have been able to ascertain neither the CJA91 nor the 1993 Act were inserted either by way of supplement or by way of substitution to the list of enactments thus territorially extended.
 Part III of the Criminal Justice Act 1961 was repealed by the Crime (Sentences) Act 1997 – “C(S)A97” – see section 56(2) and Schedule 62 of C(S)A97. In its place, the C(S)A97 substituted, by virtue of section 41, the somewhat elaborate provisions contained in Schedule 1 to the Act.
 We do not attempt to rehearse in detail all of its provisions. But it may be observed that, as before, with the exception of certain transfers from islands within the Channel Islands or the Isle of Man the process of transfer is an administrative one, involving discretion on the part of the Secretary of State whether to grant an application by a prisoner. No criteria to guide that discretion are stated. The schedule introduced the categories of “restricted” and “unrestricted” transfers. The distinction between the two categories is set out in paragraph 6(1) of the Schedule:
“6(1) For the purposes of this Part of this Schedule, a transfer under Part I of this Schedule –
(a) is a restricted transfer if it is subject to the condition that the person to whom it relates is to be treated for the relevant purposes as if he was still subject to the provisions applicable for those purposes under the law of the place from which the transfer is made; and
(b) is an unrestricted transfer if it is not so subject.”
 The notion of “the relevant purposes” is thus of some materiality. It is defined, so far as relevant to a convicted prisoner, in sub‑subparagraphs (b) and (c) of subparagraph (2) of paragraph 6 of Schedule 1:
“(b) in relation to the transfer of a [convicted] person under..., the purposes of his detention under and release from his sentence and, where applicable, the purposes of a supervision and possible recall following his release; and
(c) in relation to the transfer of a person’s supervision under paragraph 4(1) or (2) above, for the purposes of his supervision and possible recall.”
The term “recall” is further defined in paragraph 6(3):
“(3) In this paragraph ‘recall’ means –
(b) in relation to a person who is supervised in pursuance of a condition contained in a licence, being recalled to prison under the licence, whether for a breach of any condition of the licence or otherwise.”
It is also necessary to note the terms of some of the provisions of paragraph 15 of Schedule 1 to the C(S)A97. The provisions of sub-paragraph (2) were an essential element in the reasoning adopted by the sentencing judge in reaching the conclusion that he had been given power to make the order under section 16 of the 1993 Act which he made. Subject to sub‑paragraph (3) of paragraph 15, sub‑paragraph (2) of paragraph 15 provides as respects a person, transferred under inter alia the provision whereby the appellant was transferred, to any part of the United Kingdom or to any of the Channel Islands that:
“...he shall be treated for the relevant purposes as if his sentence had been an equivalent sentence passed by a court in the place to which he is transferred.”
Sub-paragraph (3) states;
“(3) A person who has been sentenced to a sentence of a length which could not have been passed on an offender of his age in the place to which he has been transferred shall be treated for the purposes mentioned in sub-paragraph (2) above as the Secretary of State may direct.”
However, subject to correction, it appears to us that the only provision within Schedule 1 which touches on the powers or jurisdiction of the courts is paragraph 18, which states:
“18(1) The powers of a court in any part of the United Kingdom to order that the term of any sentence of imprisonment passed by the court shall commence at or before the expiration of another term of imprisonment shall include power to make such an order where that other term was imposed by sentence of the court elsewhere in the United Kingdom or in any of the Channel Islands if the offender –
(a) is serving that other sentence in that part of the United Kingdom; or
(b) is for the time being present in that part of the United Kingdom by virtue in order under the Schedule, or is unlawfully at large in the law of country of island in which that other sentence was passed.”
 Pausing at this point in the legislative history, there is, we think, nothing in either the Criminal Justice Act 1961 or the C(S)A97 as it was enacted, which indicated that Parliament intended the discretionary, administrative exercise of transferring a sentence within the British Isles to confer on the courts of the part of the United Kingdom to which a person might be transferred the power or jurisdiction to order that person to be returned to prison to serve a part of a sentence imposed by the court in the original jurisdiction.
The Crime and Disorder Act 1998
 It is however necessary next to consider the Crime and Disorder Act 1998 – “CDA98” – since a provision within a schedule to it is also central to the decision of the sentencing judge in this case that he was vested with the power or competence to make an order respecting the sentence imposed by the court in England.
 The CDA98 is a lengthy enactment much of which extends only to England and Wales. However, in Schedule 8, which is concerned with “minor and consequential amendments” there are to be found a number of amendments to the C(S)A97 – see paragraphs 130 to 139 of Schedule 8. In particular, paragraph 135(2)(b) of that Schedule 8 amends sub-paragraph 3(b) of paragraph 6 of Schedule 1 to the C(S)A97 – which we have set out at paragraph  above- thus:
“In paragraph (b), for the words ‘recalled to prison under the licence’ there shall be substituted the words ‘recalled or returned to prison’.”
 The sentencing judge in this case took the view that by virtue of that amendment, read with paragraph 15(2) of Schedule 1 to the C(S)A97 – also set out in paragraph  above - he was empowered to make an order under section 16 of the 1993 Act in respect of the sentence imposed in Carlisle.
 As we have just indicated, as respects the point of jurisdiction or competence with which this appeal is concerned, the crucial amendment to the definition of the “relevant purposes” occurs within the schedule of “minor and consequential” amendments. It may be observed that there are within the various sections contained in the CDA98 a number which touch on the treatment of offenders and the release of prisoners. The CDA98 introduced the notion of extended sentences. The provisions for England and Wales are in the fasciculus of sections 58 to 60. The annotator to the Current Law publication of statute comments in relation to section 60 on the possible difficulties of its interface with section 40 of the CJA91 (return to prison on a new conviction). The Scottish provisions are in sections 86 to 88. Part V – “Miscellaneous and Supplemental” – contains in sections 99 to 105 provisions amending or supplementing the early release provisions of CJA91; and sections 111 and 112 contain amendments of the 1993 Act and the insertion of what is now section 204A of the Criminal Procedure (Scotland) Act 1995 (restriction on consecutive sentences on released prisoners). Both the Scottish amendment and the amendments for England and Wales deal with the early release of prisoners following their having been returned to prison by virtue of an order of the court. However, so far as we are able to decern, there is no substantive provision expressly giving power to a court in one constituent part of Great Britain (let alone other parts of the British Isles) to make orders respecting a sentence imposed in another such part.
 While at first sight the argument advanced to and accepted by the sentencing judge has some attraction, it is in some respects largely based on a prima facie, literal reading, albeit one has to seek elsewhere a context for the meaning the word “return”. That is, of course, not to say in any way that the argument is not deserving of fullest consideration. But as the discussion developed before us, it became evident that there were certain countervailing considerations. These, perhaps understandably, had not been canvassed before the sentencing judge.
 In summary, first, as already observed, the legislative provisions respecting the early release and return of reoffending prisoners in both England and Wales and Scotland recognise and respect the independence of the respective legal systems. A person convicted and released in one jurisdiction is not liable to be returned by judicial order were he to offend during the period of his licence in another jurisdiction. At least prior to the enactment of the amendment to paragraph 6(2)(b) of Schedule 1 to the C(S)A97 by paragraph 135(2)(b) of Schedule 8 to CDA98, that constitutional respect for the independence of the taking of judicial decisions in the legal systems was observed in what were essentially administrative arrangements flowing from an administrative or executive decision to transfer a prisoner.
 Secondly, that amendment – central to the view of the sentencing judge- is within a schedule of “minor and consequential” amendments. Where the principal provisions of the statute in question do not make any clear change in the policy or structure of previous legislation, amendments described as consequential or minor are not normally to be construed as intended to change that policy or structure - cf Craies on Legislation particularly at paragraph 14.3.11; Benyon on Statutory Interpretation, at page 272, in the commentary on S82. In contrast to the term “recall”, which is given a detailed definition in paragraph 6 of Schedule 1 to CSA 97, the relevant schedule of CDA98 does not attempt a definition of what is meant by “return”. In particular, it does not seek to define “return” by reference to any of the primary provisions in any of the jurisdictions which enable the exercise of a judicial discretion on whether, and if so, the extent to which a prisoner may be returned to serve an unexpired part of the original sentence. There is no transitional provision, or avoidance of retroactivity, such as might have been expected had it been intended to confer a new jurisdiction on the courts (cf paragraph 14 of Schedule 9 to the CDA98).
 Thirdly - as Mr Fyffe stressed in the course of his well presented written and oral submissions- starting from the requirement in subsection(1) of section 16 of the 1993 Act that the person concerned should have been sentenced by a court in Scotland, the later provisions of section 16 of the 1993 Act defer to the hierarchy or criminal courts within Scotland and do not adapt to the Scottish courts’ purporting to make an order in respect of a sentence passed by a court in England and Wales. Conversely, were the consequential amendment in Schedule 8 of the CDA98 to have the import which was accepted by the sentencing judge, that would appear to involve conferring a power on the English court to order a return in respect of the Scottish sentence. That would arguably be inconsistent with the limited power given in the 1993 Act to such a court to refer the matter back to Scotland.
 Fourthly, as was also pointed out by Mr Fyffe, a Scottish court seeking to exercise its discretion in respect of the unexpired part of an English sentence may not have available to it the appropriate information respecting the original offence; and in some instances may not fully appreciate the legislation in question.
 Despite the length of this opinion we should make clear that we do not claim to have conducted an exhaustive examination of all the legislative provisions or to have noted all possible arguments either in favour of the approach of the sentencing judge or in favour of the appellant. But, as we indicated at the outset, we are satisfied that there is an important question of statutory interpretation which does not give an obvious answer and which therefore should properly be considered by a larger bench. What we have said is in the hope of assisting that consideration and is not in any way intended as a limitation on that debate.
 We shall therefore continue this appeal for such a hearing. Parties should lodge at least one week before that hearing such further notes of argument as they consider appropriate.
 For completeness, in paragraph 4.14 of its report the Kincraig committee considered the possibly of a prisoner, convicted of the original offence in Scotland committing a new offence south of the the border; but, in line with its principal recommendation that return be mandatory, and not dependent on the exercise of judicial discretion, the committee suggested an automatic administrative trigger.