The Trinamul Congress on Wednesday expelled dissidents Sachhidananda Banerjee and Tanima Chatterjee who had filed nominations as Independents for the polls to the Calcutta Municipal Corporation.

Trinamul sources said while multiple rounds of back-channel parleys with Banerjee had failed, no such attempts were made with Chatterjee, a sister of deceased stalwart Subrata Mukherjee.

“The tone had to be set with the Calcutta civic polls. Elections to 110-odd civic bodies lie ahead of us. We cannot afford proliferation of Trinamul dissidents contesting as Independents, thereby helping the Opposition through division of pro-Trinamul votes,” said a Trinamul vice-president.

Banerjee — the chairman of the Calcutta Municipal Corporation between 2010 and 2015 — had unsuccessfully contested the 2015 civic polls as a Trinamul candidate from ward 70.

Chatterjee was initially nominated by the party in ward 68, but was soon replaced to accommodate the outgoing councillor Sudarshana Mukherjee.

Ratan Malakar, the third dissident — who had filed nominations as an Independent from ward 73, where Mamata Banerjee’s sister-in-law Kajari Banerjee is the party’s official candidate — withdrew his candidature last week and reaffirmed his commitment to the party.

Malakar, a councillor for two decades, attributed his decision to requests from the top-tier leadership. Sources in the party said Malakar decided to withdraw after discussion with Trinamul’s national general-secretary Abhishek Banerjee, a nephew of candidate Kajari Banerjee.