In the House of Commons the Prime Minister appealed directly to the Unionists to put their doubts to one side and go for a deal that promised the prize of the complete disarmament of the IRA.
He appealed to them not to reject the failsafe assurances he offered to ensure that Sinn Fein leaders will be expelled from a power-sharing executive "within weeks" if General John de Chastelain reports that the IRA was reneging on promises to begin decommissioning.
"After 30 years of bloodshed, grief-stricken families, terror-torn communities, is it not worth waiting 30 days to see if the undertakings made here are fulfilled?" Mr Blair said.
In a further attempt to lever the Unionists into accepting an agreement, the Prime Minister's official spokesman later said that all parts of the agreement, including the controversial prisoner releases, would be re- examined if the decommissioning understandings are not borne out and the deal collapsed. "We will review prisoner releases should we get to that situation," he said.
In another development yesterday the Parades Commission banned the Orange Order from marching down the nationalist end of the Ormeau Road in south Belfast on 12 July. The decision came just hours after the Order kept the peace at Drumcree after being banned from the nationalist Garvaghy Road on Sunday.
The Commission said that failure of the Orangemen to engage fully in local discussion with the local residents' group was behind its decision.
Most of the noises from Mr Trimble's party have been negative about the peace plan put together last week, which holds out the prospect of the IRA possibly decommissioning its entire arsenal by May next year. However, he and most of the leading spokesmen have not ruled the deal out of court, pressing instead for stronger assurances that the republicans would not benefit if it turned out to be a bluff.
The focus is now on detailed negotiations over the legislation, which could be rushed through Parliament after the 15 July deadline to allow devolved powers to be transferred on 18 July. The legislation will allow the executive to be suspended at any stage if General de Chastelain is not convinced the IRA intends to decommission totally by 22 May 2000. He will report in September, December and May next year.
Mr Blair, as reported in The Independent yesterday, moved further to meet the Unionist demands for more guarantees by announcing that the proposed power-sharing executive could continue without Sinn Fein if the IRA failed to begin decommissioning within days of a deal being signed.
Outlining the deal, Mr Blair told MPs: "Should default occur, the institutions are suspended automatically whilst we find a way forward. We are all then, in effect, back to where we are now. But with these two vital differences - the blame for default is clear, and the parties are then free to move on in an executive without the defaulting party." For that to work, it would require the nationalist SDLP to sit in the executive while Sinn Fein was excluded and it was not clear last night that John Hume, the SDLP leader, was prepared to do that. Pressed earlier yesterday on the issue, Mr Hume declined to contemplate the prospect of failure.
But Mr Trimble said that, by calling on his party to join an executive before the IRA had handed over any of its guns and bombs, Mr Blair was leaving the political initiative with the terrorists.
"You are asking us to sacrifice the democratic principle to expediency and you are asking us to take a gamble on an ineffective and unfair safety net," he warned Mr Blair.