Northern Ireland Brexit challenge dismissed

Members of the public, media, legal profession and political sphere descended en masse this morning to the Royal Courts of Justice to hear the eagerly anticipated judgment on Northern Ireland’s legal challenge to Brexit. The case, taken by a prominent victims’ rights campaigner and local politicians, is one of several challenges arising out of the UK’s referendum decision earlier this year to leave the EU. There are separate proceedings ongoing before the English Courts and the Northern Ireland Court was careful to stress that it was not duplicating issues which are going to be dealt with in those English proceedings.

In a structured and detailed 45 page judgment, Mr Justice Maguire surveyed the NI constitutional landscape over the last 400 years. The challenge to Brexit was framed by the applicants on the basis that the UK government could not use its prerogative power to trigger Article 50 – the formal notice required by EU law to start Brexit – but rather primary legislation by the UK parliament, amongst other things, was required.

Maguire J had five main issues to consider:

  1. Is an Act of Parliament required to trigger Article 50(2) of The Lisbon Treaty rather than simply prerogative power?
  2. If an Act of Parliament is required, then must the NI Assembly pass a motion consenting to the new legislation first?
  3. Are there wider public law issues that would restrain the exercise of prerogative power e.g. the requirement to take specific NI considerations into account and not to give excessive weight to the referendum result?
  4. Has the Northern Ireland Office failed to carry out an equality impact assessment on the effect of Article 50(2) being invoked?
  5. Can Article 50 be triggered without the consent of the Northern Irish people? This last question was based on the Applicants’ contention that the Good Friday Agreement indicates there should be no change in constitutional status without this consent.

The application in respect of all 5 issues was dismissed.

The court did not consider that the provisions of the Good Friday Agreement or specific Northern Ireland legislation would override or supersede the use of prerogative power in the circumstances. Much of the wider public law issues considered and the equality impact assessment argument were also thought to be outside of the realm of Judicial Review or a little premature in light of the fact that Article 50 simply begins a process, the full particulars and consequences of which are not yet known.

In short, the court ruled that there is nothing peculiar about the position in Northern Ireland that would prevent the Prime Minister from starting the Brexit process without approval from the NI Assembly, or the people of Northern Ireland. The extent to which Brexit affects the constitutional settlement here, which is the substantive underlying issue, is however to be determined by the process and negotiations which follow the Article 50 notice.

The applicants have already indicated their intention to appeal the decision made today, and that appeal could be heard by the Supreme Court, in conjunction with the other UK challenges, as early as December.

A full copy of the judgment is available here.

For further information contact, or any member of the litigation team.


While great care has been taken in the preparation of the content of this article, it does not purport to be a comprehensive statement of the relevant law and full professional advice should be taken before any action is taken in reliance on any item covered.