Lawyers argue Northern Ireland can veto Brexit
Two lawyers in Belfast cited the terms of the historic 1998 peace deal on Tuesday in arguing Northern Ireland has the right to veto Britain's decision to leave the EU.
"Sovereignty over constitutional affairs has been ceded" with the signing of the Good Friday Agreement, according to lawyer Ronan Lavery.
The barrister is representing a cross-party group of politicians in their legal challenge against the result of the June 23 referendum which saw Britain vote to leave the European Union.
"The people of Northern Ireland have control over constitutional change, it cannot be imposed upon the people of Northern Ireland," he added.
Northern Ireland and Scotland voted to remain in the EU, but the result was swung towards Brexit by a leave vote in England and Wales.
Lavery's view is matched by lawyer Ciaran O?Hare, representing victims? rights campaigner Raymond McCord, who is also challenging London's decision to forge ahead with Brexit.
Northern Ireland fears a hard border could be reintroduced with the Republic of Ireland when Brexit becomes a reality, which is expected to happen in 2019.
Prime Minister Theresa May announced on Sunday the government would trigger Article 50 of the EU's Lisbon Treaty no later than March 2017, which would begin two years of negotiations leading to Britain's exit.
Lavery said after Brexit any attempt to unify Northern Ireland and the Republic would be subject to the other EU member states granting permission for Northern Ireland to join the bloc.
"That is a practical and illegal impediment to the nationalist aspiration for a United Ireland," he said, warning that Brexit could more broadly have a negative impact on the peace accord.
"Withdrawal from the EU could have a catastrophic effect on the peace process and that delicate constitutional balance which we have reached," Lavery said.
But any attempt to see Northern Ireland plan its own future away will be opposed by London, with the government already stating the UK would be united in leaving the EU.
"We voted in the referendum as one United Kingdom, we will negotiate as one UK, and we will leave the EU as one UK. There is no opt-out from Brexit," May said on Sunday.
"And I will never allow divisive nationalists to undermine the precious union between the four nations of our United Kingdom."
The legal challenge in Belfast is due to conclude on Wednesday.
The 1998 Good Friday peace accords largely ended the three decades of violence in Northern Ireland, known as the Troubles, in which 3,500 people were killed.