The Ulster Unionist leader, Mr David Trimble, is likely to face another effective leadership challenge at an Ulster Unionist Council next month.
It is being convened to vote on a motion that there should be no disciplinary action against the three dissident MPs led by Mr Jeffrey Donaldson.
The 60 signatories necessary to call another meeting of the 860-member UUC have been presented to party headquarters in Belfast, unionist sources said.
It will be for the 14-member officer board to decide whether the UUC should take place. However if the signatories and the wording of the motion are in order, the meeting must go ahead under party regulations.
"It looks like we'll be back at yet another UUC in early to mid-September," said one source.
This move by the anti-Belfast Agreement wing of the party again puts serious pressure on Mr Trimble's leadership.
It may also render ineffective the continuing efforts by senior Ulster Unionists Sir Reg Empey and Mr Jim Rodgers to find middle ground between the dissident MPs - Mr Donaldson, Mr David Burnside, party president the Rev Martin Smyth and Mr Trimble.
The party leader has just returned from summer holidays and, according to confidants, is buoyant and prepared for this latest challenge. "His opponents can do what they like but one thing is for certain, David Trimble is not resigning as party leader under any circumstances," said a senior Ulster Unionist source who supports Mr Trimble.The source said that "on balance", the UUC is likely to proceed but cautioned that in most cases, disciplinary matters were ultimately for the UUP 110-member executive as opposed to the UUC and that the officer board could reject the requisition for another council. He acknowledged, however, that the wording could be framed in such a manner as to ensure the UUC takes place.
The UUP officer board is due to meet early next week to decide on whether a special committee should proceed with a disciplinary case against Mr Donaldson, Mr Burnside and Mr Smyth, who are accused of acting against the interests of the party by resigning the party whip in Westminster. They face expulsion.
This latest UUC meeting could result in that disciplinary action being put on hold pending the outcome of the council vote.
With each challenge, more party centrists, while generally supporting the policy position of Mr Trimble, are querying whether the constant feuding will lead to the UUP's implosion.There are those opposed to the agreement and Mr Trimble who support Mr Donaldson, those who maintain faith with the agreement and Mr Trimble's leadership, and the group in the middle who are torn between the two sides, but fear the destruction of the UUP if the repetitive internal battles persist.
Mr Donaldson will require some of this middle group to switch to his side to win a UUC vote. Based on the 440 pro-Trimble and 369 anti-Trimble votes at the June UUC, that would require at least 36 Ulster Unionists abandoning their leader.
Mr Donaldson is due to meet Sir Reg and Mr Rodgers today to discuss the attempts of the latter two to broker some form of detente between the two wings of the party. The decision by Donaldson supporters to press ahead with another UUC however indicates there is little prospect of rapprochement.