A victims campaigner's claim that the United Kingdom cannot quit the European Union without the consent of the people of Northern Ireland is to go before the supreme court in London.
Senior judges in Belfast today agreed to refer the contention at the centre of Raymond McCord's failed legal challenge to the Brexit process for further judicial consideration in London.
Mr McCord, whose son was murdered by loyalist paramilitaries, was jubilant at the outcome.
He said: “This has vindicated everything I have been trying to do.
"The people of Northern Ireland should be deciding whether we stay in the EU or leave - 56 per cent of the people here voted to remain."
His case will now advance to the supreme court alongside another unsuccessful legal bid to halt Brexit mounted by a cross-party group of MLAs.
Five issues of devolution are expected to come under scrutiny when those proceedings get underway next month.
Earlier this week Northern Ireland's Attorney General, John Larkin QC, referred the judicial review brought by Stormont politicians including Alliance MLA David Ford, SDLP leader Colum Eastwood, Sinn Fein Assemblyman John O'Dowd and Steven Agnew of the Green Party.
Mr McCord’s lawyers sought permission to leapfrog the Court of Appeal and join them in putting their case before justices sitting in London.
The Belfast-based campaigner claims the Good Friday Agreement has given the Northern Irish public sole sovereignty to decide on their future.
His legal team predict that Brexit will cause constitutional upheaval and have a “catastrophic effect” on the peace process.
Nationalist aspirations to become part of the United Ireland and unionist desires to remain in the UK are both catered for in the Northern Ireland Act 1998.
The supreme court will now consider whether withdrawal from the EU without the consent of the Northern Ireland population impacts on those provisions.
“This is a major step forward for our people and for victims,” Mr McCord said outside court.
“The three judges believe I have a right to an opinion, unlike political people who have criticised me.”
British prime minister Theresa May is set to trigger Article 50 of the Lisbon Treaty, the formal process for confirming the UK is to leave, by the end of March 2017.
Even though the June 23rd referendum backed Brexit, a 56 per cent majority of voters in Northern Ireland wanted to remain.
Last month a High Court judge in Belfast dismissed separate proceedings issued by Mr McCord and the Stormont politicians.
Mr Justice Maguire rejected claims that the British government cannot use royal prerogative powers to begin EU withdrawal without an Act of Parliament.
But earlier this month the high court in London held that only parliament can trigger Brexit.
With the Government set to challenge that ruling at the supreme court, lawyers in the Northern Ireland cases now have their own appeal routes mapped out.
During a court hearing last week counsel for the government claimed any move to split the two cases could ultimately prove to be a “treacherous shortcut”.
Meanwhile the supreme court annunced on Friday that both the Scottish and Welsh governments are to be allowed to intervene in a court battle over how the Brexit process should be formally triggered.
Counsel for the Scottish government is being invited by the supreme court justices to address the court on the relevance of points of Scots law so far as they do not form part of the law of England and Wales