Maguire J said (para 9) - "In view of the overlap between the respective challenges the court, on the application of the intended respondents, sought to avoid these proceedings simply duplicating those in England and Wales. Accordingly the court has stayed the consideration of the central issues which the English courts will deal with. Instead, these proceedings have sought to concentrate on the impact of Northern Ireland constitutional provisions in respect of notice under Article 50 and it is with this subject that this judgment is concerned."
The court addressed five issues which related solely to the constitutional arrangements in Northern Ireland. The issues were:
ISSUE 1: The applicants contend that the prerogative power cannot be exercised for the purpose of notification of intention to withdraw from the EU in accordance with Article 50(2) TEU because it has been displaced by the Northern Ireland Act 1998 read along with the Belfast Agreement and the British-Irish Agreement and other constitutional provisions. The applicants contend that, in these circumstances, an Act of Parliament is required to trigger Article 50(2).
ISSUE 2: If an Act of Parliament is required, there is a requirement for a Legislative Consent Motion to be granted by the Northern Ireland Assembly before such legislation could be passed authorising notification in accordance with Article 50(2) TEU.
ISSUE 3: There are a variety of public law restraints on any exercise of prerogative power in any event. These include issues about the requirement to take all relevant considerations into account and not to give excessive weight to the referendum result.
ISSUE 4: There has been a failure by the Northern Ireland Office to comply, prior to notification being given under Article 50 TEU, with the terms of section 75 of the Northern Ireland Act 1998 and with the terms of its own equality scheme.
This judgment does not conclude the Northern Ireland case because of the issues "held over." The case is almost certain to end up being heard by the Supreme Court of the UK along with an appeal from the High Court.
So far then, a decisive "win" for the government.
George Peretz QC of Monckton Chambers has published a very helpful summary of the Northern Ireland decision.
Earlier post re the Northern Ireland litigation