The Ulster Unionists have pledged to re-form a branch of the party in Kilkeel, Co Down, after the local association vowed to dissolve in protest at the Trimble leadership.
Some 26 members of the party, meeting in the town's Orange hall on Monday night, walked away from the party complaining that the UUP and its leaders were out of touch with unionists in the Mourne area.
Those who left included Mr James Donaldson, father of the Lagan Valley MP, Mr Jeffrey Donaldson, who quit the party in December and joined the Democratic Unionists earlier this month.
The Donaldson family is still based in the area.
Mr Maynard Hanna, the UUP secretary in Kilkeel, said: "The party and its leadership have no identity whatsoever with the unionist populace on the ground."
Mr Donaldson snr said yesterday he would consider his future. It is understood his joining the DUP remains an option.
The move follows a similar walkout by 30 party members in Mr Trimble's constituency association in Upper Bann last weekend.
The leader's party association called a vote of no-confidence in Mr Trimble last July, and 37.5 per cent supported the motion.
Last week the DUP claimed that more than 100 Ulster Unionists in neighbouring Lagan Valley had defected following a high-profile rally headed by Mr Jeffrey Donaldson.
Mr Donaldson snr had been a UUP candidate in South Down in last November's Assembly election, but was involved in a bitter dispute with the former environment minister, Mr Dermot Nesbitt, who headed the party ticket in the constituency.
As a result of their dispute rival posters calling for first-preference votes for both men appeared in parts of the constituency - often in the same street.
The UUP now holds just one of the six Assembly seats in the constituency, which used to be represented by the late Enoch Powell, who held the Westminster seat by a comfortable majority.
Mr Gerry Douglas, a senior unionist in the constituency and a Trimble loyalist, said last night that the local branch in Kilkeel would be re-formed within the week.
"We will have another association up and running there without any bother," he said.
Mr Nesbitt said the flow of members away from the UUP would be countered by an influx of new members loyal to the leader and to party policy.
So far, the Donaldson defection has cost the UUP one Westminster seat, making the DUP the largest unionist party in the Commons; three Assembly seats; and at least 150 members.