The North's political leaders entered talks in Scotland aimed at restoring power sharing this afternoon with the threat of having devolved institutions abolished if they fail to reach agreement.
Northern Ireland politicians have reached decision time over devolution, British Prime Minister Tony Blair said this evening tonight.
As he and Taoiseach Bertie Ahern prepared to get the first session of intensive talks under way at St Andrews, Mr Blair said he believed the political will was there among the Northern Ireland parties.
"Essentially everyone understands this is the crucial moment for this whole process", he said.
"We have been almost 10 years working on this, myself and the Taoiseach. There has been an immense amount of progress made but now is the time to get the business done."
Northern Ireland politicians will have three days of intense negotiations which will determine if there will be a deal on devolution. Ultimately Democratic Unionist leader, the Rev Ian Paisley, will decide if a four-party executive is possible.
British Prime Minister Tony Blair
However, he will need to be convinced that the IRA is committed to abandoning terrorism and criminality for good and he will also require Sinn Fein to change its policy on policing and endorse the Police Service of Northern Ireland.
Sinn Fein, for its part, insists there needs to be a clear signal from the DUP that it is willing to form a power-sharing government with them if it is to call a special conference to change its policing policy.
Mr Blair said tonight: "We know the issues we have to resolve in terms of power-sharing, in terms of policing. "All of these issues are well gone over. The ground has been gone over many times.
"The question is whether there is the will to make sure we resolve any outstanding issues and get agreement and give people in Northern Ireland the future they want. I believe the political will is there to do it. The discussions in the coming hours will decide."
"It is enormously important I think, that we have some sense, that this is really the moment to decide." Mr Ahern said it was the collective view of most governments that there was not a better time to bring all the issues remaining in Northern Ireland to a conclusion.
As the two Prime Ministers prepared to enter the Robert Louis Stevenson Rooms at the Fairmont Hotel in St Andrews for the first session of the talks, he said: "What we want to do is to get the Assembly, the executive, power sharing in Northern Ireland, working for the benefit of people in Northern Ireland.
"We will give our very, very best effort to achieve that over the next few days." There was tight security around St Andrews for much of the day as the two prime ministers and the Northern Ireland Assembly party arrived at the university town amid the hordes of golf tourists who had come to play its celebrated links courses.
The conference venue was for much of the day shrouded in mist but both governments will be hoping the fog over power-sharing and policing in Northern Ireland will lift soon.
Bemused American golf tourists who had booked in to the luxury five star £58 million hotel, golf resortand spa where the talks are being held were forced to go through metal detectors and stringent security measures to get to their rooms.
Taoiseach Bertie Ahern
As they relaxed in the bars, unionists, nationalists and cross community politicians from the Northern Ireland Assembly mingled in the foyer.
Mr Blair and Northern Ireland Secretary Peter Hain flew to the venue from London, landing at RAF Leuchars.
They had come fresh from Prime Minister's Questions and Northern Ireland Questions where Mr Hain ruled out any discussion on the controversial issue of so-called on-the-run paramilitaries returning to Northern Ireland.
Republicans have long harboured hope that a deal would enable IRA members who fled Northern Ireland to avoid arrest to one day be allowed back.
There was a small protest from members of the group Fair (Families Acting for Innocent Relatives) which campaigns on behalf of those bereaved by IRA violence.
Willie Fraser, their spokesman, held a placard at the gates of the Fairmont demanding No Amnesty For Terrorists and dubbing the Northern Ireland Secretary Sinn Hain.
PA