Raymond McCord, whose son was killed by loyalist paramilitaries in 1997, has lodged an application for judicial review at the High Court in Belfast.

His solicitor, Ciaran O’Hare of McIvor Farrell Solicitors, said: “As a victim of the most recent conflict in Northern Ireland, Mr McCord is very concerned about the profoundly damaging effect that a unilateral withdrawal of the UK from the EU will have upon the ongoing relative stability in Northern Ireland.

“He is concerned that any withdrawal would be contrary to the UK’s international law obligations pursuant to the Good Friday Agreement. He is also concerned about the abrogation of his fundamental rights that withdrawal will entail.

“In the alternative, any notification under Art 50 should at least be done lawfully and constitutionally, in particular by way of a prior mandate from Parliament.”

Mr O’Hare added: “Mr McCord’s application is an important constitutional case which engages the Northern Irish public interest in a way that no other case has or is likely to for many decades.”