Ulster Unionist Party leader Mr David Trimble is to face a vote of no confidence in his constituency next week.
Last month dissidents in the Upper Bann constituency gathered 30 signatures to call a special meeting to put forward a motion of no confidence in Mr Trimble as their MP.
The motion, to be debated on July 8th, was tabled amid the row between Mr Trimble and anti-Belfast Agreement colleague Mr Jeffrey Donaldson in the run up to a meeting of the party ruling Ulster Unionist Council.
Mr Donaldson failed at the meeting to get the council to back his demand for members to reject the British and Irish government's Joint Declaration plans for the restoration of devolved government.
Motions of no confidence in Mr Trimble and Mr Donaldson were tabled by rival factions in their two constituencies on the same day.
However the one against Mr Donaldson was withdrawn following the UUC vote "in the interests of party unity".
Since then Mr Donaldson, with fellow dissident MPs Mr David Burnside and the Rev Martin Smyth, have resigned the parliamentary whip and been suspended from the party pending a disciplinary hearing later in the month.
Mr Arnold Hatch, chairman of the UUP's Upper Bann constituency, said there were 260 delegates in the association and that Mr Trimble's opponents had provided five more signatories to their requisition of a special meeting than required under the rules.
He declined to say how he thought the meeting would go. "My duty is only to call the meeting," he said.
Mr Hatch added: "There is a lot of frustration in the constituency that needs to be addressed.
"Some people might find it irksome, but members have a right to call a meeting if they feel there is an issue that needs to be addressed."
Mr Trimble made no comment today, but an aide said he was confident of retaining the support of his association and would be mounting a "robust defence" of his policies on the peace process.
PA