Posters were put up against BJP leader Rajib Banerjee in Howrah's Domjur on Wednesday, terming him a "traitor" amid speculation over his future political move.
The posters, allegedly put up by local Trinamool workers, stated that Mr Banerjee, who switched over to the BJP ahead of the assembly elections, was not welcome to join back the party.
The posters came up a day after the former Trinamool minister warned members of his new party in a social media post that "people will not take kindly to threats of President's rule" against a government elected with a huge mandate.
He has also skipped a meeting of the state BJP on post-poll violence, adding further fuel to the speculation.
"Rajib Banerjee is corrupt and a traitor. We urge the party leadership that he should not be taken back," a local Trinamool worker said.
Domjur MLA Kalyan Ghosh said TMC supporters don't want Mr Banerjee to return to the party.
"They have told me about this. It is true that he had betrayed the party," he said.
Mr Banerjee lost the Domjur seat as a BJP candidate by around 42,000 votes to Mr Ghosh.
The BJP discarded the matter as an internal affair of the Trinamool. "TMC and corruption are synonymous. Until he had joined BJP, such allegations were never made. However, it is an internal matter of the TMC," a BJP leader said.