The DUP has made clear it will "battle" to get the Brexit vote put into practice, notwithstanding the London supreme court judgment that Westminster must vote on triggering article 50 of the Lisbon Treaty to take the UK out of the European Union.
DUP MP Sammy Wilson expressed disappointment at the ruling that British parliament can vote on article 50, because it "has given the ability to those anti-democratic losers within the Remain camp to conduct a parliamentary guerrilla warfare against the decision by the people of the United Kingdom to leave the EU".
He welcomed the ruling that Stormont and the Scottish and Welsh devolved institutions could have no veto over Brexit.
"The battle now commences at Westminster and as far as the DUP is concerned, we will be using our votes and voice to ensure a rapid commencement on the negotiations to leave the EU, completely as the prime minister promised, while at the same time ensuring that in the absence of any Assembly voice . . . the issues most concerning to Northern Ireland are articulated by our MPs," said Mr Wilson.
Victims’ campaigner Raymond McCord, however, called on the DUP to respect the wishes of the 56 per cent majority in the North who voted Remain. Mr McCord, who was part of the supreme court Brexit challenge, said he feared that DUP MPs would “put party first and people second”.
“Because 56 per cent voted in Northern Ireland in favour of remaining within the EU, the DUP should vote for what the majority want,” he said.
Sinn Féin president Gerry Adams said the supreme court judgment underlined the need for Taoiseach Enda Kenny and the Government to "uphold the Remain vote in the North".
Mr Adams said the Government must negotiate with the “other 26 EU members the right of citizens in the North to a special designated status within the European Union”.
“Brexit will undermine the institutional, constitutional and legal integrity of the Good Friday Agreement. It puts the British government on a collision course with the EU in which our stability and economic progress are regarded as collateral damage,” he said.
SDLP leader Colum Eastwood said the ruling significantly undermined the value placed on the democratic mandate of the Northern Assembly. "Northern Ireland voted to remain in the European Union, yet the Northern Ireland Assembly is being denied any role or rights in the upcoming negotiations with the European Union," he complained.
Ulster Unionist Party MPs Tom Elliott and Danny Kinahan, in a joint statement, said: "The challenge now is to secure the best deal for Northern Ireland. It is clear that the failed DUP/Sinn Féin Executive, which has crumbled after eight months, is incapable of addressing Northern Ireland's unique needs in Brexit negotiations."
Former Alliance leader David Ford said the ruling that the three devolved assemblies did not need to be consulted "does raise significant issues for the future of devolution across the UK on a wide range of issues and not just membership of the EU".
Green MLA Steven Agnew welcomed the ruling that the British parliament will have its say on Brexit. "Despite the supreme court rejecting the devolved institutions argument, today represents a victory for democracy and the rule of law," he said.
Traditional Unionist Voice leader Jim Allister "greatly welcomed" the supreme court's rejection of the "nonsense idea" that Stormont and the devolved institutions in Scotland and Wales should be consulted on or even have a veto over Brexit.