Mr Justice Maguire has set aside 4 and 5 October to hear legal challenges to Brexit in the Northern Ireland High Court, with campaigners and a cross-party group of MPs separately arguing that it would be unlawful to trigger Article 50 of the Lisbon Treaty without the approval of the UK Parliament. In court on Friday, Maguire J announced his plan to stay grounds of challenge in common with the proceedings in London until judgment is delivered in those cases. He asked lawyers in the Northern Ireland actions to try to agree on all remaining issues which he will then have to determine.

The legal team for Raymond McCord will argue that Brexit is contrary to the UK’s domestic and international treaty obligations set under the Good Friday Agreement. In a separate action, a group of MLAs led by Steven Agnew of the Green Party will dispute the legality of the Brexit process, citing a number of conditions which, they claim, must be satisfied before Article 50 can be triggered.