Northern Ireland's devolved assembly has been suspended for nearly two years
Northern Ireland's devolved assembly has been suspended for nearly two years AFP

Northern Ireland's assembly in Belfast looks set to be restored this weekend following almost two years of political deadlock, the leader of the biggest pro-UK party said on Thursday.

The Democratic Unionist Party's Jeffrey Donaldson said he had informed the devolved power-sharing assembly's speaker that they were prepared to end their two-year boycott.

The move paves the way for the British province's first pro-Irish nationalist first minister to be appointed, seen as a historic milestone nearly three decades after a 1998 peace deal.

The DUP walked out on power-sharing around two years ago in protest at post-Brexit trading arrangements that they said risked cutting Northern Ireland adrift from the rest of the United Kingdom.

But this week they announced that they backed a deal with the UK government in London to break the deadlock.

MPs in London unanimously backed the proposals on Thursday.

"I expect the Assembly will meet on Saturday following the Speaker consulting and making all the necessary arrangements," said Donaldson.

Saturday's sitting should see Sinn Fein's Michelle O'Neill selected as a new first minister, after her nationalist party won assembly elections in May 2022.

It will be the first time a pro-Irish nationalist politician will hold the post in the UK territory since the assembly was re-established under the terms of the 1998 Good Friday Agreement.

That deal ended three decades of sectarian violence over British rule.

The DUP will take up the deputy first minister position as the second-largest party. Both operate as joint heads of government and run the executive.

Unionists have argued that trading arrangements, whereby Northern Ireland remained subject to some EU rules despite the rest of the UK having left the bloc, threatened the province's sovereignty.

At issue were port checks on goods moving to and from Great Britain -- England, Scotland and Wales -- and Northern Ireland, to protect the integrity of the European single market and customs union.

Northern Ireland has the UK's only land border with the EU -- with the Republic of Ireland to the south -- but the peace deal stipulated that it has to be kept open, with no infrastructure.

Donaldson said the deal brokered with the UK government in London had effectively removed the so-called Irish Sea border, to ensure no barriers to the UK internal market.

But there remains some opposition from more hardline unionists who have called it a "surrender deal", arguing that it keeps Northern Ireland in an economically united Ireland.

Brussels has said it will "analyse carefully" details of the new deal between the UK government and the DUP published on Wednesday.