Mr David Trimble seems likely to have to make a judgment on the IRA's weapons offer without a definite British government commitment on the final legal title of Northern Ireland's new police service.
The long-awaited Policing Bill implementing the Patten reforms of the RUC will be published at Westminster this afternoon, and changes demanded by the Ulster Unionists are not expected to appear on the face of the Bill.
In an article in this morning's Irish Times, the Northern Secretary, Mr Peter Mandelson, says he has "kept faith both with the broad intentions of the (Patten) report and with the detailed recommendations".
Confirming his intention to proceed with Patten's proposal to scrap the RUC's "royal" title, Mr Mandelson says: "As I said in January, the police service will no longer be known as the RUC when the first recruits selected under the new arrangements begin their training in the autumn of 2001. If I could achieve the objective of a new beginning for policing without this change, I would do so."
However, Mr Mandelson says the original Patten proposal has been "wrongly" taken as "an insult" and "tantamount to disbandment". And in a clear attempt to boost Mr Trimble ahead of Saturday's meeting of the Ulster Unionist Council, Mr Mandelson declares: "It is important to dispel both these thoughts and I am giving consideration to how this might be done."
This was being taken last night to mean that - as with the question of the cap badge for the new police service - the final decision on its title might also be deferred, with a decision to be taken by the Northern Secretary after further consultation with the parties represented on the new Police Board.
However it was being made clear that any decision on title or cap badge would require "maximum consensus". And Mr Trimble's critics are certain to argue that the SDLP and Sinn Fein may be expected to prove as trenchant in support of Patten in any future consultation as they have to date.
With tension mounting within his party, one of Mr Trimble's supporters in the Assembly commented that opinion would be unaffected by yesterday's announcement of the RUC George Cross Foundation Fund, and that any deal on the future title should be defined in the legislation coming before parliament.
Despite official denials, the Ulster Unionists insist they reached an agreement with Mr Mandelson during the recent Hillsborough negotiations that the Policing Bill would define the new service as "The Police Service of Northern Ireland (Incorporating the RUC)".