Britain, Ireland and the United States on Tuesday welcomed a deal to end almost two years of political deadlock in Northern Ireland that will, for the first time, hand the territory’s top leadership role to Sinn Fein, a party that mainly represents Roman Catholic voters committed to a united Ireland.
The breakthrough came in the early hours of Tuesday morning when the Democratic Unionist Party, whose largely Protestant supporters want to remain in the United Kingdom, said it was ready to end a lengthy and crippling boycott of Northern Ireland’s political assembly.
“I believe that all the conditions are now in place for the assembly to return,” said Chris Heaton-Harris, Britain’s secretary of state for Northern Ireland on Tuesday.
Claire Cronin, the U.S. ambassador to Ireland, said she welcomed the news. “The people of Northern Ireland are best served by a power-sharing government in Stormont as outlined in the Good Friday Agreement,” she wrote on social media, adding that President Biden “has long made clear his support for a secure and prosperous Northern Ireland.”
Ireland’s foreign minister, Micheal Martin, said the imminent restoration of power-sharing was “good news” and that he looked forward to working with the assembly in the future.
The deal between the Democratic Unionist Party, or D.U.P., and the British government opens the door to a seismic change in the politics of modern day Northern Ireland, where the first minister has, up to now, always been drawn from the ranks of the D.U.P.
Barring last minute complications, Sinn Fein, which emerged as the largest party in Northern Ireland’s last elections, will now nominate the first minister. The D.U.P. will have to settle for the deputy first minister post, a big symbolic change even if the powers of the holders of those posts are similar.
The unionist party walked out of the Northern Ireland Assembly in February 2022 in protest of post-Brexit trade arrangements laid out in a deal called the Northern Ireland protocol, which imposed checks on goods arriving from mainland Britain.
The restrictions were introduced because Ireland remained in the European Union when the British quit. The system avoided checks at the politically sensitive land border between Ireland and Northern Ireland — a frontier where violence flared during the decades of sectarian strife, known as the Troubles, which largely ended after the Good Friday Agreement in 1998.
But many unionists saw those controls as an affront and worried that they would drive a wedge between the territory and the rest of the United Kingdom.
In 2023, Rishi Sunak, Britain’s prime minister, struck a new deal with the European Union, known as the Windsor Framework Agreement, which won some concessions from Brussels.
But they were insufficient for the D.U.P., whose continued boycott of Stormont paralyzed decision making even as civil servants maintained the basic functions of government.
Pressure has been steadily rising on the D.U.P. to cut a deal. Northern Ireland’s health service has been in crisis and its dysfunctional politics prevented public sector workers from receiving pay increases offered throughout the rest of the U.K. Earlier this month, tens of thousands took part in the largest strike in Northern Ireland in living memory.
The D.U.P.’s decision to return to government was announced after a fractious internal meeting — part of which was leaked on social media — that lasted more than five hours and dragged into Tuesday morning.
At around 1 a.m., Jeffrey Donaldson, the D.U.P. leader, told a news conference that his party was ready to return to the assembly, promising to “work alongside others to build a thriving Northern Ireland.”
In exchange London has pledged new measures to reduce checks on goods traveling between mainland Britain and Northern Ireland, though the detail is not scheduled to be made public until Wednesday. In addition, Mr. Heaton-Harris said that Northern Ireland would gain more than £3 billion in funding.
Mr. Donaldson’s pledge to restore power sharing is conditional on the British government fulfilling its side of the agreement and pushing through legislation swiftly, something Mr. Heaton-Harris promised to do in his statement on Tuesday, saying: “I can confirm that we will stick to this agreement.” The detail of the deal will be watched closely, however.
On Tuesday Mr. Donaldson said that the outcome of negotiations with London was that there would be “zero checks, zero customs paperwork” on goods moving to Northern Ireland from mainland Britain. “That takes away the border within the U.K. between Northern Ireland and Great Britain,” he said.
Those words may have been carefully chosen as, even if there is “zero customs paperwork” required, form filling unrelated to customs may be necessary.
For Mr. Donaldson, cutting a deal is a political risk, and Monday night’s internal meeting exposed divisions within the D.U.P., with some prominent party figures opposed to the agreement.
Some critics fear the party will be outflanked by a more hard-line party called the Traditional Unionist Voice, which is opposed to compromise.
Its leader, Jim Allister, said on Tuesday in a social media post that “in betrayal of their own solemn pledges, the D.U.P. has caved in” over trade rules for the Irish Sea. It seemed that “not one word of the union-dismantling protocol has been removed,” he added.
By contrast there was a mood of optimism from Sinn Fein, whose president, Mary Lou McDonald, said the breakthrough had been “a long time coming, but we’re very pleased that we’re at this juncture.”
She added that she looked forward to her colleague Michelle O’Neill becoming first minister of Northern Ireland.
“That will be a moment of very great significance,” said Ms. McDonald as she stood alongside Ms. O’Neill in the Great Hall of Stormont on Tuesday, “not simply because we haven’t had government for so long but because it will be the first time that we will have a Sinn Fein first minister, a nationalist first minister.”