The ministerial offices are ready, the civil service advisers and backup teams have been assigned, the official cars wait in their garages like panthers at rest. All aspects of Northern Ireland devolution are in place and have been for some time: all that remains is for David Trimble and his Assembly team to throw the switch and the machinery of the inclusive power sharing administration will come into operation.

The next three days will be a long, nail-biting time for everyone. Today, Mr Trimble is expected to meet Mr Blair at Downing Street to discuss the "failsafe" legislation and presumably other matters. The meeting of the Ulster Unionist executive on Friday last has been adjourned until Wednesday evening. That should see a final decision being made on whether to go for the deal or not.

There is also the delicate matter of the Democratic Unionist Party motion at the Assembly to exclude Sinn Fein from office. This has 29 signatures at the moment but one more is required, under Assembly rules, before it can be debated. There is a question-mark over the prospect of securing that vital 30th signature, which would have to come from the UUP, but if it were forthcoming then a day would probably be allocated for a debate.

This would postpone the ministerial nominations until Friday. If the UUP decides to make the quantum leap of faith and go with the Blair-Ahern Way Forward document, we could have 10 shiny new ministers by the end of the week. Devolution of powers is meant to go through on Sunday, which would turn Monday into a most interesting day, with Martin McGuinness telling the world's media how he will approach his new portfolio and the DUP taking up its two ministries but refusing to sit at the cabinet table with Mr McGuinness.

There is no talk of a formal ceremony to mark the devolution of powers. Given the composition of the proposed power-sharing executive, it is unlikely that a Royal laying-on of hands would be universally welcomed at this stage. Besides, the Assembly is expected to be in recess until September.

There have been varying reports of the Glengall Street meeting of the executive before the weekend. "Nothing happened," said a pro-agreement member who was in attendance. There had been predictable speeches from people on opposing sides of the argument but there was "no nastiness". Anti-agreement sources said: "It went well from our point of view. It was obvious that the mood was not with Trimble." For both sides, Friday was a holding operation: the real "Clash of the Titans" should take place on Wednesday evening.

There have been encouraging developments from a pro-agreement viewpoint. The latest Irish TimesMRBI opinion poll indicated there was still a strong moderate element in the UUP. While there may be some incidents at the "Twelfth" celebrations, the prospects for a relatively peaceful day look reasonably good. Up to now, it has been a remarkably low-key and restrained marching season and this is bound to have a knock-on effect in the political sphere. The corollary of this is that a sudden outbreak of widespread street violence could have serious consequences for the UUP leadership. "If it's a good Twelfth, tempers will be cooler," was how one senior unionist put it.

The "failsafe" legislation is due to be published today. Mr Blair and his colleagues may decide to accept unionist amendments to show his genuine concern for their fears but he will need to be careful not to alarm the republican constituency which is currently quite nervous on this score. Legislation is always tricky and maintaining the necessary balance will not be easy. There would have to be consultation with Dublin about any proposals with legislative implications for the Oireachtas, reflecting the dual nature of the current process.

This afternoon, Sinn Fein's chief negotiator, Mr McGuinness, is to meet representatives of the US National Security Council at the White House to give his party's perspective on events. While the Castle Buildings negotiations were held in private, Mr McGuinness and his colleagues - principally the party president, Mr Gerry Adams, Mr Martin Ferris and Mr Gerry Kelly - appear to have impressed their interlocutors in the two governments with their commitment to the principle of decommissioning as part of the full implementation of the Belfast Agreement.

"Appeasers," say the anti-agreement forces. Not so, say senior negotiators who sat across the table from Sinn Fein. They point out there have already been two ceasefires and that Sinn Fein changed its constitution to permit members to sit at Stormont. The scepticism in the media and elsewhere about Sinn Fein's intentions is not shared by senior figures on the official side in the negotiations, who praise what they describe as the "courage" of Mr Adams and Mr McGuinness and their commitment to the new institutions, with all their "prizes and pain". They also speak very favourably of Mr Trimble and what they see as his courageous stance against the rejectionists in his party.

Much play has been made of the possibility of an IRA statement. These pronouncements tend to come out of the blue but republican sources said they had no indication that "P. O'Neill" was about to speak. Political insiders said it was "highly significant" that the pseudonymous republican spokesman had said nothing negative or critical in relation to recent developments.

While there is undoubtedly a considerable amount of unease in the republican ranks, fuelled by a lack of clarity on the commitments given by their political leaders in the talks, reports from different quarters say there is no sign of mutiny or a split. Mr McGuinness was reassuring activists in New York yesterday; a previous meeting in the city during the week was described as lively but not fractious. The audience included some notable "hard men" but no significant expressions of dissent were reported.

Speculation continues over the future of Dr Mo Mowlam. While a re shuffle is widely expected by the end of the month, there were no indications that she was likely to be "sacrificed" this week as a gesture to the unionists. Apart from any other consideration, her popularity in the British Labour Party would seem to make that unlikely. Neither Dublin nor the SDLP would wish to see her badly treated. "There would not have been a Good Friday agreement without her," senior Dublin sources maintained.

It is said that Dr Mowlam covets the post of Foreign Secretary and has been resisting the idea of becoming Labour Party chairwoman. The list of possible successors in what may turn out to be a pared-back post as Northern Secretary grows daily if not hourly, including such names as Mr Paul Murphy, Dr Jack Cunningham, Mr Nick Brown and Mr Peter Mandelson.

The adjournment of the unionist executive meeting until Wednesday night appears pointless unless there is a serious prospect that the party will go with the Way Forward. It seems clear that the party leadership would like to oblige the Prime Minister but not at the expense of their own skins. A quiet Twelfth and good footwork by the British government on the legislation will improve the prospects for compromise. As a senior negotiator put it over the weekend: "It's all to play for."