Ulster Unionist and Sinn Féin negotiating teams have been exchanging draft papers on key issues as Mr Gerry Adams and Mr David Trimble today embark on a further round of head-to-head discussions aimed at securing a political breakthrough.
UUP and Sinn Féin sources said that both sides, spurred on by the British and Irish governments, were seriously engaged in trying to strike a comprehensive deal that would result in elections directly leading to a working Executive.
Any deal must hinge on the IRA committing itself to ending activity, with Ulster Unionists in return guaranteeing to maintain the stability of the Executive and Assembly.
Any IRA pledge is likely to be backed up by a third and more persuasive act of decommissioning.
The decommissioning body said yesterday that no such act has taken place, but a spokesman confirmed that the head of the body, Gen John de Chastelain, returned to Belfast yesterday.
Talks sources continue to say that real progress has been made. Despite concerns that republicans might only sign up to a partial deal that would not satisfy the majority of unionists, Sinn Féin and the UUP were striving for an all-embracing agreement that would build trust throughout the community.
"We are on the cusp of possibly getting a deal. We are at the last hurdle, but that is often the most difficult to surmount," said a senior Ulster Unionist figure yesterday.
"We are going for a deal, not half a deal," said a senior Sinn Féin source.
He confirmed that such was the level of the engagement over the dozen or so meetings between Mr Trimble and Mr Adams over recent weeks that draft papers were being exchanged between both sides.
It is understood these deal with matters such as policing, the devolution of justice and policing, stabilising the institutions of the Belfast Agreement, human rights and other matters.
"There has been an exchange of concepts and positions, but we have not closed on any issue," said the Sinn Féin source.
The British Prime Minister, Mr Tony Blair, and the Taoiseach, Mr Ahern, presided over a Downing Street summit involving the UUP and Sinn Féin delegations on Monday.
The US special envoy to Ireland, Mr Richard Haass, has marked the first anniversary of the suspension of the Northern institutions with a positive assessment of the efforts to kick-start the political process.
Mr Haass, speaking on his 11th visit to Ireland in his three years as President Bush's peace process troubleshooter, said the Downing Street meetings on Monday were of a "higher quality" than anything he had witnessed so far.
"There is a genuine desire to bring this to closure, to put into place the remaining pieces of the jigsaw. Do I think there is a commitment to make this work? Yes. Do I think it will work? Yes."
He said there were two vital differences between political efforts now and those which failed in the spring. These were what he called the widespread view that elections were in the interests of all, and the establishment of the International Monitoring Commission.
He said the commission was a product of the Joint Declaration, and a resource for anyone with a complaint against any party to the Belfast Agreement.
Mr Haass held a round of bilateral meetings with the Northern parties yesterday following his participation in the Downing Street talks on Monday.
The SDLP was critical of the decision not to include it in the Downing Street talks.
Mr Mark Durkan, the party leader, said his party's role should not be taken for granted, and he complained the party had been excluded because it was not a "problem party" and had no paramilitary wing.
The Women's Coalition also complained of exclusion, and warned of the dangers of concluding deals behind closed doors.
Ms Monica McWilliams said: "We have never seen a workable solution result from behind-the-door secret deals. It only creates suspicion and confusion. If the British and Irish governments want a transparent and positive outcome that all parties will agree to, it is time they learnt to start with a transparent and inclusive process."
The Alliance deputy leader, Ms Eileen Bell, said she was concerned at the emphasis being placed on the roles of the Ulster Unionists and Sinn Féin.
"Exchanges between the UUP and Sinn Féin should be tightly limited to overcoming the particular problems of trust and confidence that exist between them. It should not be taken for granted that all parties will necessarily accept the outcome of any negotiations."
The DUP deputy leader, Mr Peter Robinson, said any deal concluded would not stick because it would be "cobbled together for electoral purposes".
Mr Haass yesterday also met the Progressive Unionists led by Mr David Ervine, and the decommissioning commission headed by Gen de Chastelain.