The UUP leader, Mr David Trimble, met the British Prime Minister, Mr Tony Blair, at Downing Street yesterday and stressed the need for reassurance on the "crucial" issues of consent, decommissioning and confidence-building measures ahead of the party's executive committee debate on Saturday.
The party also urged the British government to act against what it called "a tidal wave of republican triumphalism" over recent weeks, which culminated in the "regrettable" decision by the US government to suspend the deportation of six convicted IRA men.
The UUP leadership is nearing the end of its consultation process to decide if it should boycott multi-party talks or, as the executive committee is expected to recommend, that it should opt for "proximity talks" on a "time-limited" basis.
When he emerged from the meeting with Mr Blair, Mr Trimble was asked if his party had come to a decision on joining multi-party talks. "That's not a question I can answer at this stage," he said. "The party executive will be meeting on Saturday and I hope we will have a full consideration of the issues then."
Although Mr Trimble refused to be drawn on the party's decision, assurances from the British government on the issue of consent and "other confidence-building measures" will be crucial to the outcome of Saturday's meeting.
Mr Trimble said the discussion with Mr Blair focused on confidence-building measures "which we regard as the guiding principle governing the talks".
"I think we would want to put the focus on the people of Northern Ireland. It is not a matter of us asking for something to be done for the Ulster Unionist Party. Our concern is that the people of Northern Ireland should be reassured that any process, whether it is this talks process or any talks process, shall be conducted with due regard for basic democratic principles and with the objective of ensuring genuine peace. These are crucial matters."
Later, Downing Street refused to comment on whether Mr Blair had given the Ulster Unionists the reassurances they sought.
The Church of Ireland Bishop of Down and Dromore, Dr Harold Millar, has urged the UUP to take part in all-party talks. He said they would lose out if they were not involved from day one.