Free Party (Vabaerakond) chair Andres Herkel says malicious intent is behind the recent wave of party board resignations.
Pärnu branch member of the eight-seat parliamentary party, Heli Kunnapas, recently demanded sweeping change to both board and leader.
Jaanus Ojangu stood down in Tallinn in August, soon followed by four more members.
Dissent has spread to the south-eastern branch, which has communicated a similar line.
Herkel not budging
Mr. Herkel remains defiant, however.
"The board of the Free Party was elected less than four months ago and is legitimate,'' he told the south-eastern branch.
''However, I strongly disapprove of a malicious practice where several board members stood down, attempting to damage the party's reputation and trigger new elections," he went on.
"The board's composition has changed four times since 2015, more than with other parties," he added.
Mr. Herkel enjoys some support though. Several members stated on Thursday that they would stay put and rejected a no-confidence motion.
Mr. Herkel nonetheless admitted issues which need resolving face-to-face.
"The problem is how to fill the empty board places when potential replacements are not responding to invites to do so,'' he said, noting a solution has been touted for the next AGM.
Kaul Nurm, named as a potential future leader, says a clean sweep of the board is prerequisite to his running.
The Free Party has eight seats in parliament, but only has around 600+ members (threshold membership for registered parties is 500).
Other parties riven with discord include the Social Democratic Party (SDE), which former minister Urve Palo quit altogether in August, and the Centre Party, where Narva city council members defected, starting a new political group.
Editor: Andrew Whyte