This is cutting it fine as the Belfast Assembly is due to meet the following day to discover whether the party will agree to plans for the immediate formation of a devolved government that includes both Unionists and Sinn Fein.
Senior party sources said afterwards that the party did not seem inclined to accept the proposals but that everything would hinge on the text of the draft registration which the Government is due to produce next week.
The legislation will be designed with fail-safe mechanisms meant to ensure that Republicans do not renege on decommissioning promises. One source said: "It all depends on the legislation and on what the prime minister promises between now and Wednesday. He may come up with wonderful guarantees for us, we don't know."
At its meeting yesterday the party's executive committee endorsed Mr Trimble's description of the Government proposals as "fundamentally unfair and unbalanced". It also called on the IRA and other groups to begin actual decommissioning immediately and to complete the process by May 2000.
Meanwhile, Orange Order leaders were under new pressure to think again before defying the Parades Commission with threats to lead up to 20,000 men into a park close to Belfast's Ormeau Road.
Even though they are prepared to agree a route which would keep the parade away from the nationalist district, security chiefs fear troublemakers spoiling for a confrontation will attempt to leave Ormeau Park.
Senior RUC officers have drawn up contingency plans to deal with any violence.
Tens of thousands of other Orangemen will also take to the streets throughout the rest of Northern Ireland on Monday to commemorate the 1690 Battle of the Boyne.
Security on the Republic's side of the Irish border has also been tightened, with strengthened police checkpoints on all major north-south roads.
The Orangemen changed the traditional route of the Belfast parade, which normally ends on the southern outskirts of the city, because of plans for a mass rally in the park to protest against the decision to stop Orangemen from Ballynafeigh marching through the neighbouring lower Ormeau.
Ulster Unionist councillors had talks yesterday with Alistair Graham, the chairman of the Parades Commission which ordered them to stick to the traditional route and keep out of the park.
But nationalists believe violence is inevitable if the march, which is at least five times bigger than Drumcree, goes ahead in that part of the city and then develops into a huge stand-off.
Negotiations involving all sides, including the Belfast Lord Mayor Bob Stoker, are expected to go on right up until the start of Monday's march.Reuse content