A new deal will mean no checks on most goods crossing from Great Britain to Northern Ireland, the DUP leader says
Sir Jeffrey Donaldson says goods staying in Northern Ireland will not need checks or customs declarations
He says more details will be announced tomorrow - adding that it is a "significant change" in trade arrangements
Donaldson announced the agreement in the early hours of Tuesday - which paves the way to power-sharing in Northern Ireland being restored
The DUP started boycotting NI's devolved power-sharing government nearly two years ago in protest at trade arrangements after the UK left the EU
Sinn Féin Vice President Michelle O'Neill calls it "day of optimism", and the UK says "all the conditions are now in place" for the NI Assembly and executive to return
Sir Jeffrey Donaldson continues his interview with BBC Radio Ulster, explaining that the agreement ends "dynamic alignment with EU law".
“In other words, all new EU law applied automatically to Northern Ireland – that will now come to an end," he says.
Sir Jeffrey Donaldson tells Good Morning Ulster that he expects full details of what's being agreed with Westminster to be published as early as tomorrow.
He says post-Brexit legislation has created an Irish Sea border for goods within the UK, and that “these new arrangements remove those restrictions".
“Are these proposals perfect? Have we achieved everything we wanted to achieve? No we haven’t.”
He adds that his party will continue to "fight for further changes".
The DUP leader is now on the BBC's Good Morning Ulster programme.
Sir Jeffrey Donaldson says this is "undoubtedly a decisive moment" for his party and a "good outcome for Northern Ireland".
He adds: "I’m delighted that we’ve been able to make the progress that we have.
"I believe there is now a route to have the devolved government restored."
Image source, PA MediaNaomi Long says institutional reform is 'essential'
While we wait to hear from Sir Jeffrey Donaldson, we can bring you more reaction from another of Northern Ireland's parties.
Alliance Party leader Naomi Long says this morning represents a day of "mixed of emotions".
"Good we might finally get to do the whole job we're elected to do and try to repair some of the damage done, but the last 24 hours don't bode well for long-term stability," she writes in a social media post.
She adds: "Institutional reform is essential, we just cannot sustain further chaos or collapse."
Image source, PA MediaDUP leader Sir Jeffrey Donaldson is due to speak to our colleagues on BBC Radio Ulster's Good Morning Ulster programme shortly - we'll bring you any key lines on this page.
Donaldson has been in politics since he was a teenager.
He worked as a constituency agent for the South Down MP Enoch Powell (famous for his 1968 "Rivers of Blood" speech) in the mid-1980s, before becoming a personal assistant to the former UUP leader James Molyneaux.
It was representing the UUP that he was first elected, in 1985, to the Northern Ireland Assembly representing South Down.
Sir Jeffrey was highly critical of the Good Friday Agreement - the 1998 peace deal which ended the conflict in Northern Ireland known as the Troubles - and warned his leader David Trimble against supporting it.
In 2003, after years of refusing to support party policy and supporting failed bids to oust Trimble, he quit the party and defected to the DUP.
He was appointed to the Privy Council, a body which advises the monarchy, in 2007, and was awarded a knighthood in 2016 for political service.
He was heavily involved in talks to reach a Brexit deal with the EU, and in 2021 became leader of the DUP.
Image source, PA MediaThe principle of power-sharing is what sets Northern Ireland apart from the UK's other nations.
It means that in any government there must be representatives from both the nationalist community - who favour unity with the Republic of Ireland - and unionists, who want Northern Ireland to remain part of the UK.
How does it work in practice?
A chamber of 90 members (MLAs) is elected to the assembly at least once every five years.
Northern Ireland has a first minister and a deputy first minister - one unionist, the other nationalist.
The executive, or cabinet, is multi-party - and ministers are drawn from unionist, nationalist and non-aligned parties, based on how many seats they have won in an election.
This also means that politicians from smaller parties can be appointed as ministers.
Image source, PA MediaThe tánaiste (Irish deputy prime minister) Micheál Martin has welcomed the DUP's decision.
Writing on social media, he says: "The imminent return of the assembly and executive is good news for the people of Northern Ireland, and the Good Friday Agreement."
He adds that he is "looking forward" to working with both in the future.
Jayne McCormack
NI political correspondent
Image source, Getty ImagesA statue of Edward Carson at Stormont
In Northern Ireland politics we are used to burning the midnight oil and last night was no exception.
But what happens now the DUP is officially backing a deal?
It’s thought the UK government could bring legislation to Parliament later this week, and could be passed very quickly.
The secretary of state will then - with agreement from the Northern Ireland parties - request a recall of the Stormont assembly in order to allow a speaker to be elected and a first and deputy first minister to be nominated.
There’s no date confirmed for this yet but the legal deadline for forming an executive is 8 February and there’s talk this could happen before the week is out.
Watch this space - but after many false dawns, it seems the sun is set to rise on Stormont again.
The DUP leader Sir Jeffrey Donaldson announced the agreement in the early hours, after a five-hour meeting at the Larchfield estate in County Down.
A 'defining time' for Northern Ireland's place in the UK - Donaldson
Image source, PA MediaAlliance Party MP Stephen Farry reacted to the news on social media
Stephen Farry, the deputy leader of the Alliance Party, says Northern Ireland is "a more hopeful and better place this morning".
Writing on social media, he says "a lot of damage" has occurred in the last two years and "much work lies ahead".
"This episode has further illustrated the fundamental instability in our institutions and reinforces the need for reform," he writes.
Image source, PacemakerWestminster's Northern Ireland Secretary Chris Heaton-Harris has called the move by the DUP a "welcome and significant step".
"I am grateful to [party leader] Sir Jeffrey Donaldson and colleagues for the constructive dialogue over the past months and to the other political parties in Northern Ireland for the patience they have shown during this time," he said.
Heaton-Harris said he was pleased the DUP had agreed to a "package of measures that the UK government has put forward" and were ready to return to the Northern Ireland Assembly.
He acknowledged that the move was subject to an agreement with the UK government.
"I now believe that all the conditions are in place for the Assembly to return; the parties entitled to form an executive are meeting tomorrow to discuss these matters and I hope to be able to finalise this deal with the political parties as soon as possible."
Gareth Gordon
NI political correspondent
Image source, PA MediaIt was nearly one in the morning when Sir Jeffrey Donaldson emerged from a five-hour meeting of his party executive to confirm he was leading the DUP back into power-sharing government after no less than 726 days.
It was a moment for those who claimed he lacked political courage to perhaps think again.
However, while this was a triumph for the DUP leader's negotiating skills both with his party and Westminster, it may yet come at a price for the former Ulster Unionist MP.
The remote Larchfield Estate was used for the party's executive meeting to strike a deal. It was chosen for its security. Those attending weren't even given the location until three hours before it started.
But what greeted Sir Jeffrey and others will have been familiar to many DUP politicians of a certain age: crowds singing Loyalist songs, Union flags on poles and cries of "sell out".
This time, however, it was all directed inwards.
It was the beginning of a very uncomfortable night.
Image source, PA MediaProtesters outside the meeting last night
Sinn Féin was the largest party after the most recent assembly elections. Party leader Mary Lou McDonald said she was "optimistic" following the DUP's decision.
"It is vital there is political stability to address the scale of the crisis across our public services," she said.
"Let's now focus minds on the job at hand and to the solutions required to support workers and families who want and deserve functioning government."
Should power-sharing return, the party's vice-president Michelle O'Neill is in a position to become the first nationalist first minister of Northern Ireland.
Chris Page
Ireland correspondent
A hundred and thirty members of the Democratic Unionist Party executive met for more than five hours last night.
Protesters gathered outside the venue in County Down, urging the DUP not to agree to a new deal to restore the devolved government.
But at 01:00 GMT, Sir Jeffrey Donaldson held a news conference to announce he had won support for a plan to bring back power-sharing.
He said the question of how soon that would happen depended on when the UK government fulfilled its commitments – including passing legislation.
“It is a matter for the government how quickly now they wish to move with those steps, what I require is for them to make those steps," he said.
"We will judge how we progress, and then we will make our move when the time is right.”
Image source, Getty ImagesSir Jeffrey said the details which would be published in the coming days, would show how Northern Ireland’s place in the UK’s internal market had been secured.
The DUP has argued that checks on goods crossing the Irish Sea amounted to an economic border with Great Britain.
After the DUP’s decision, the Northern Ireland Secretary Chris Heaton Harris said he hoped to finalise the agreement as soon as possible.
The Sinn Féin President Mary Lou McDonald said she was optimistic the devolved institutions would be back up and running before the legal deadline next Thursday.
Good morning and welcome. We are restarting our live coverage following some significant news out of Northern Ireland overnight.
At 01:00 GMT, the Democratic Unionist Party leader Sir Jeffrey Donaldson held a news conference to announce his party would endorse a deal to allow the devolved government in Northern Ireland to start again.
The party has been boycotting the Stormont assembly for two years - preventing power-sharing with Sinn Féin.
Donaldson said any agreement was conditional on Westminster passing laws to address Unionist concerns about post-Brexit trading rules.
Ministers in London say they hope to finalise the deal as soon as possible.
So stick with us as we bring you all the latest news lines and analysis.
Ciaran McCauley
BBC News NI
That's all from us on a night that appears to point Northern Ireland firmly back on the road towards restored devolved government.
There's still a way to go - parties are due to meet later on Tuesday to discuss what comes next, and the DUP's deal is subject to the government fulfilling its end of the agreement.
But it does mean there's a chance things move quickly towards the return of power-sharing institutions at Stormont.
There'll be plenty more to say on this first thing in the morning and you'll be able to get all the latest on the BBC News NI website, BBC Newsline and the Good Morning Ulster programme from 6.30am.
In the meantime, thanks for joining myself, Rebekah Wilson and Jake Wood.
A mammoth, five-hour meeting and the late breaking news that the DUP has agreed to return to devolved government - all in all, it was one of those nights (and early mornings) in Northern Ireland politics.
Here's a recap of everything that happened:
We've heard reaction to tonight's late breaking news from the likes of TUV leader Jim Allister and Sinn Féin leader Mary Lou McDonald - and the late hour hasn't deterred some others from giving their take.
SDLP leader Colum Eastwood welcomed the deal in a post on X, saying "let's get the workers paid and the waiting lists down now then".
Former Northern Ireland Secretary Julian Smith, also posting on X, says today is "a day of hope".
Meanwhile Labour's Shadow Secretary of State Hilary Benn says this is "good news for NI".
Writing on X, external, he adds: "The task now will be for all of us to support the new power-sharing executive."
Image source, PAAs we reported earlier, the Traditional Unionist Voice (TUV) party has been one of the main opponents to the DUP's potential deal.
Its leader Jim Allister took to X (formerly Twitter) to give his reaction to tonight's proceedings.
"Sadly, in betrayal of their own solemn pledges, the DUP has caved in on an Irish Sea border, EU law and the suspension of Article 6. Seems not one word of the Union-dismantling Protocol has been removed."
Image source, PA MediaParty leader Mary Lou McDonald says she feels "optimistic" about getting the institutions back up and running, following the news that the DUP has endorsed a deal.
"Sinn Féin will now engage with the parties and both governments to ensure we now all press on without delay.
"It is vital there is political stability to address the scale of the crisis across our public services."
She says it's time to "focus minds on the job at hand and to the solutions required to support workers and families who want and deserve functioning government".