The British government will introduce legislation on Thursday formally authorising Brexit negotiations after the supreme court ruled it cannot invoke article 50 of the Lisbon Treaty without parliamentary approval.
The Bill will face amendments in both houses of parliament but is likely to be passed within two weeks, enabling prime minister Theresa May to trigger article 50 before the end of March, as planned.
Brexit secretary David Davis told MPs on Tuesday the legislation would be "as straightforward as possible" but would not be drafted in such a way that substantive amendments would be impossible.
An overwhelming majority of MPs voted last month in favour of Mrs May's March deadline, and Labour has promised not to block the article 50 notice, although some of its MPs are likely to join Liberal Democrats and Scottish Nationalists in voting against the government.
On Tuesday, the supreme court in London decided by a 8-3 majority that only parliament could withdraw the rights conferred on British citizens by EU membership, which was authorised by the European Communities Act in 1973.
The 11 justices ruled unanimously, however, that the devolved legislatures in Scotland, Wales and Northern Ireland could not veto the start of negotiations or Brexit itself.
No bearing on Brexit
The court also ruled that section 1 of the Northern Ireland Act, which guarantees that a vote by a majority of the Northern Ireland electorate to leave the UK must be respected, has no bearing on the decision to leave the EU.
"This important provision, which arose out of the Belfast Agreement, gave the people of Northern Ireland the right to determine whether to remain part of the United Kingdom or to become part of a united Ireland," the court said.
"It neither regulated any other change in the constitutional status of Northern Ireland nor required the consent of a majority of the people of Northern Ireland to the withdrawal of the United Kingdom from the European Union. "
Minister for Foreign Affairs Charlie Flanagan welcomed the British government's assurance there would be no delay to the start of Brexit negotiations, despite the court decision.
However, Sinn Féin leader Gerry Adams said the judgment underlined the need for Taoiseach Enda Kenny to "uphold the Remain vote in the North" by seeking a special designated status within the EU for Northern Ireland.
In the Dáil, Taoiseach Enda Kenny said Brexit would not affect the rights of citizens of Northern Ireland. “The circumstances we have are special,” he said.
Scotland's first minister, Nicola Sturgeon, said the need for a second independence referendum was becoming "ever clearer" in the wake of the ruling that Westminster does not have to consult the devolved Scottish parliament before triggering article 50.
“This raises fundamental issues above and beyond that of EU membership,” Ms Sturgeon said.
“Is Scotland content for our future to be dictated by an increasingly right-wing Westminster government with just one MP [lawmaker] here? Or is it better that we take our future into our own hands?”
Six-year process
The British government hopes to negotiate its withdrawal from the EU and agree a new trade deal within the two-year timeframe set out in article 50.
However, Minister for Finance Michael Noonan told the Irish Times corporate tax summit in Dublin that he expects the entire process to take at least six years from exit talks to the negotiation of a new trade deal.
The Government has undertaken an “extensive programme of engagement” with all other EU governments and EU institutions to outline Ireland’s key priorities for the negotiations, he said.
In Dublin, the European Commissioner for Economic Affairs, Taxation and Customs, Pierre Moscovici, insisted that Britain’s post-Brexit arrangements must be “inferior “to EU membership.
“You cannot get the best of both worlds,” he said.