In a judgment released this morning (here) the High Court of Northern Ireland (Maguire J) rejected various challenges brought under Northern Ireland law to the Government’s position that it can invoke Article 50 TEU under the Royal Prerogative.
The challenges that were decided by the Court were all based on aspects of the constitutional settlement in Northern Ireland. The Court did not consider the more general issues that have been raised before the High Court in England and Wales (where judgment is awaited).
The first challenge was based on an argument that the Northern Ireland Act 1998 and the Good Friday Agreement displaced the Royal Prerogative in relation to Article 50. The Court rejected that argument: Article 50 set in train a process that might lead in a number of directions, and any change in domestic law would have to be made by Parliament. Although continuing membership by the UK of the EU was assumed at the time of the Good Friday Agreement, membership could not be described as a “constitutional bulwark” of those arrangements.
The second challenge was an argument that any legislation passed in order to trigger Art.50 would need the consent of the Northern Ireland Assembly. Given the answer to the first question, that issue was academic: but the judge did not consider that consent was a legally enforceable requirement.
The third challenge was an argument that, by reference to Northern Ireland legislation, the Government gave undue weight to the referendum result in taking the decision to invoke Article 50: the judge however considered that the decision to invoke Article 50 was of high policy and not justiciable.
The fourth argument was based on a claimed failure by the Northern Ireland Office to follow Northern Ireland equality legislation: the judge however held that the decision to invoke Article 50 could not be said to be carrying out a function relating to Northern Ireland and was outside the scope of that legislation.
The fifth argument was that the consent of the people of Northern Ireland was needed for Article 50 to be invoked: the judge found no basis for that argument.
The Northern Ireland case is likely to be joined, in the UK Supreme Court, with the (inevitable) appeal against the judgment of the English High Court. The judgment deals only with points that are distinct to Northern Ireland and generally gives little clue as to how the English case may be decided. That said, it is worth noting (a) that the Judge approached the question as a matter of statutory construction (which accords with the thrust of the Government’s submissions to the English High Court and (b) that the Judge seems to have proceeded on the basis that a notification under Article 50 was the start of a process rather than, of itself, producing changes in domestic law. Readers of this blog will remember that, in the English cases, both parties proceeded on the basis that Article 50 was irreversible. The litigation, on both sides of the Irish Sea, may well end up turning on precisely how the Article 50 process is characterised – although, for reasons I set out here I still consider it highly unlikely that the Supreme Court will need to make a reference to the Court of Justice of the EU on the question of whether an Article 50 notification can be withdrawn by the Member State concerned.