The move has now reduced the Left Front-ruled 23-member civic board to a minority and has prompted the opposition Trinamool Congress to bring in a no-confidence motion against it, sources said.
The Halisahar municipality comprises of 14 CPI(M), eight Trinamool Congress and one Congress councillors. SDO Purnendu Majhi confirmed about receiving the resignation of the CPI(M) councillors, and said the matter would be forwarded to the chairman tomorrow.
Accusing the TMC of intimidating its councillors, CPI(M) North 24-Parganas district secretary and party's Central Committee member Gautam Deb said, "Bike-borne hooligans owing allegiance to the Trinamool had attacked the houses of ten of our councillors last night and had threatened of dire consequences if they did not resign."
Denying the allegations, Trinamool district president Nirmal Ghosh said, "None of our party workers went to any CPI(M) councillor's house. They are bringing in baseless allegations against us as they are fast losing ground."
Meanwhile, Ghosh said seven Congress councillors, including the chairman of the Congress-ruled Baduria municipality, in the district have joined the TMC later in the day.