Their plan provides for Sinn Fein's inclusion in a devolved Belfast government on 15 July, to be followed within weeks by the decommissioning of arms by the IRA, with full disarmament by May next year.
It was described by Tony Blair as "the most positive opportunity for peace this land has known for years and years and years." The proposals, hammered out over five long days and nights of talks, are expected to be endorsed by Sinn Fein but there will be an anxious wait before it becomes clear whether the Ulster Unionist leader, David Trimble, can sell it to a party deeply distrustful of republican promises.
Commending it to the parties, Mr Blair laid out the timetable: "Devolution will begin. Shortly afterwards, within days, the process of decommissioning begins, both notification and authorisation that it should happen. Within weeks of that, actual decommissioning, continuing right through until complete decommissioning of all paramilitary weapons within Northern Ireland by May 2000."
Mr Blair promised that a "complete legislative fail-safe" would be put in place to ensure that both devolution and decommissioning went ahead.
Mr Trimble indicated he had continuing difficulties with the document, calling it "fundamentally unfair" in some respects and describing Mr Blair's safeguards as weak. The Ulster Unionist Party leader indicated that he looked forward to an inclusive new administration but immediately outlined a series of objections. He wanted more precise commitments from Sinn Fein, declaring: "The certainty is not there sufficiently and the guarantees are weak. We need to see the detail on this, we need to see the legislation, we need to be able to study it, and there are other matters we need to study as well. Aspects of the proposals are outside current party policy, are outside the terms of the manifesto that we stood on."
The many qualifications with which Mr Trimble tempered his welcome for the document were assumed to be a form of political insurance against inevitable internal party assaults from those opposed to any deal. The next few days are likely to see a series of intense meetings at which his party will thrash out its attitude to the deal.
The UUP went into this week's talks demanding that decommissioning be simultaneous with the formation of an executive. The deal as outlined by Mr Blair does not amount to simultaneous decommissioning, but does offer safeguards and envisages complete as opposed to token disarmament.
Sinn Fein president Gerry Adams said there would be an enormous sigh of relief not just in Ireland but throughout the world. In an appeal to Unionists, Mr Adams said: "We want to work in partnership with you. Lots of people are trying to break down and tear down what has been put together.
"We want a new future for all our people, all sections of our people. We want the Good Friday Agreement to work. That is the common ground between us. Those who don't want the future will stand in the chorus line which will put young men and women into their graves. We want to put all of the people of this island in ownership of the future."
President Bill Clinton said last night: "I think this is very welcome development. It gives us a chance to fulfill the Good Friday accords.
"It gives the people of Northern Ireland, both Protestant and Catholic, a chance to shape their destiny and government themselves. It gives us a chance to put an end to guns and violence forever."
The emergence of the blueprint came after a fifth and final day of talks, which was marked by the now-familiar mood swings from hope to pessimism as the British and Irish governments battled to reconcile Unionist and republican positions on decommissioning.
During the day General John de Chastelain produced what London and Dublin regarded as a helpful report on the prospects for decommissioning and exactly how it might be achieved. His report may now form part of a web of safeguards to ensure republicans honour their promises.
Full reports, pages 2-4 Leading article, Gavin Esler, Review, page 3,