The UK Supreme Court yesterday heard arguments that the activation of Article 50 would conflict with the Good Friday Agreement and the Northern Ireland Act 1998.

Ronan Lavery QC, acting for victims’ campaigner Raymond McCord, told the court that the Agreement is both a “binding international agreement” and “forms a written part of the constitution of Northern Ireland”.

He said: “It would be very disturbing for the people of Northern Ireland to imagine that the terms so agreed in the Good Friday Agreement were not binding to some extent, did not have a constitutional status.”

Belfast solicitor Ciaran O’Hare of McIvor Farrell Solicitors and junior counsel Conan Fegan BL are also in London for the case.

Their client, Mr McCord, argues that there cannot be any constitutional change to the status of Northern Ireland unless it is supported by the people of Northern Ireland.