Subir Ghosh (38) was knifed to death by 8-10 unidentified men as he was sitting close to the party office at Bisnupur locality under Ketugram police station area, Sub-Divisional Police Officer Sachin Makar said.
Ghosh's brother Sujit, who was present at the spot, was also stabbed and now being treated at Katwa hospital, the officer said.
District TMC leaders said the opposition Congress-CPIM murdered Subir to scare party supporters ahead of the polls but the opposition denied the charge.
The officer said all angles were being investigated and security personnel were deployed in the area.
Elections will be held in Burdwan on April 11 and 21 in two phases.
