The Democratic Unionist Party members last night voted to back a deal with Sinn Fein to save Northern Ireland's power-sharing government.
DUP leader Peter Robinson said his party's elected representatives at the Stormont Assembly had backed a deal with Sinn Fein and can now move forward on devolution of policing and justice.
Prime Minister Gordon Brown and taoiseach Brian Cowen are expected to travel to Belfast this morning to put their seal on the deal.
The deal on policing, justice and parades comes after nearly two weeks of round-the-clock talks at Hillsborough Castle, Co Down.
Flanked by DUP enterprise minister Arlene Foster and finance minister Sammy Wilson, Mr Robinson said all members of his party were behind the proposals.
Emerging from the two-hour meeting, he said: "The assembly group asked questions and considered the matter and have unanimously supported the way forward.
"Everyone present believes this is consistent with our election manifesto and pledges that we have made to the people.
"We look forward to going to Hillsborough when the document should be published."
The DUP Assembly group met for their late-night talks at Stormont amid fears that some may have rejected the deal after an earlier meeting this week where a significant number rejected proposals for an agreement.
It is now expected the British and Irish premiers will announce the details of the deal at Hillsborough Castle with the DUP, Sinn Fein and other party leaders.
Mr Robinson, standing in the Stormont parliament's Great Hall as the clock approached midnight, said he would now look to gain the support of the community and of the smaller Assembly parties for the agreement.
Sinn Fein and the DUP have been deadlocked over republican demands for the swift devolution of policing and justice powers from Westminster to Stormont, while unionists have called for an overhaul of how loyal order parades are overseen. The deal is expected to cover both issues.
Mr Robinson said: "We have a basis upon which we can go forward and recommend it (the deal) to our party, to the other parties in Northern Ireland and to the community.
"An essential element of the Democratic Unionist Party's manifesto is the requirement for community confidence, we believe this can be the basis for gaining that confidence."
The DUP's executive is expected to ratify the decision made by its Assembly members later today.
Last night's talks followed Sinn Fein's announcement yesterday that negotiations on policing, justice and parades had ended and republicans believed the basis for an agreement existed.
Sinn Fein's junior minister Gerry Kelly said: "The negotiations have come to a conclusion. We believe that it is a positive conclusion and we believe that it is the basis on which to move forward."
Sinn Fein welcomed confirmation of the DUP decision.
The party's president Gerry Adams said today: "I welcome the DUP's decision. We have been involved in what has been a lengthy stretch of negotiations.
"I commend the Sinn Fein negotiating team.
"I believe that the Assembly and political institutions can now proceed on the basis of equality, fairness and partnership. They also have to deliver for all citizens, that is the collective responsibility of all the political parties."
The announcement of a deal late last night came a day after Mr Robinson stepped back into the First Minister's office.
On Wednesday night he announced he was resuming his full responsibilities as Northern Ireland's First Minister.
A series of probes are under way after it emerged last month that his wife Iris, former MP for Strangford, secured £50,000 from two property developers to start a business for her teenage lover.
Mr Robinson was said to have known of the finances and was accused of breaching his code of office by failing to tell the relevant authorities.
The DUP leader denied all wrongdoing, but stepped down temporarily from the role of First Minister to allow time to clear his name.
He revealed on Wednesday that a legal review of the case, and of the obligations he faced as part of his duties of office, cleared him.
Critics have asked for him to release the legal review, and he has said he is preparing to do so.
But the fact that he felt secure to resume the top job was seen as strengthening his hand in efforts to deliver a deal he could sell to his party.
A little over 24 hours after the announcement, he convened last night's crunch meeting with his party that has now paved the way for a deal to secure Northern Ireland's power sharing government.