Mr David Trimble could face a new leadership challenge following his party's heavy General Election losses, it emerged today.
As Northern Ireland Secretary Mr John Reid urged politicians to step up efforts to cement the peace process, anti-Good Friday Agreement UUP sources warned that a new bid to oust Mr Trimble may come later this month.
One senior figure insisted the council election results at the start of the week were now crucial.
"If we take further reversals on local government it becomes very difficult for Trimble to put a gloss on it," the source said.
The UUP's Westminster contingent has fallen to six as five seats were lost to the Dr Ian Paisley's DUP and Sinn Fein.
The hammer blow was only slightly cushioned by Mr David Burnside regaining South Antrim and Lady Sylvia Hermon toppling the UK Unionist Mr Bob McCartney from North Down.
A legal challenge to Sinn Fein's knife edge victory over Mr James Cooper in Fermanagh and South Tyrone, which completed the republican plan to "green the west" of the Province, was today also under consideration.
Mr Cooper, who lost by 53 votes after a recount, claims polling stations in strong nationalist areas stayed open after the 10pm closing time.
A challenge to Mr Trimble's stewardship may come at the party's AGM on June 23, when he must seek re-election as leader.
PA