The Fianna Fáil national executive has dissolved the party cumann in Castlebar, Co Mayo, in a row over its affiliations with expelled TD Beverley Flynn.
The cumann angered headquarters by inviting the Independent TD to speak at a meeting in Ballinrobe.
This was in breach of orders last October by the party's general secretary, Seán Dorgan. Ms Flynn was thrown out of the party last year after failing in a libel action against RTÉ's coverage of her role in a banking scandal.
The party ard chomhairle last night voted unanimously to dissolve the Micheal O'Moráin cumann "with immediate effect".
In a statement, the executive said it was a "regrettable step" but was necessary because the cumann had "failed to demonstrate the loyalty to the party that was expected of it, under party rules and regulations.
"The ard chomhairle called on all Fianna Fáil members in Mayo to work with it over the coming weeks and months in rebuilding Fianna Fáil in Mayo," the statement said.
Fianna Fáil said a new organisation will be established in Castlebar town and the members of the Micheal O'Morain cumann would be invited to reapply for membership.
Minister for Communications Noel Dempsey is undertaking a review of party structures in Co Mayo and is expected to publish a report shortly.