++++ 1 . Failure by a Member State to fulfil its obligations - Subject-matter of the dispute - Determined during the pre-litigation procedure - Fixed definitively in the application to the Court - Subsequent enlargement - Inadmissible ( EEC Treaty, Art . 169 ) 2 . Failure by a Member State to fulfil its obligations - Pre-litigation procedure - Reasoned opinion - Time-limit communicated to the Member State - Undertaking to remedy the failure - Not met within the time-limit - Onus of proof lies on the Commission ( EEC Treaty, Art . 169 )