The poll body had earlier issued a show-cause notice to Mandal, the Birbhum district president of Trinamool Congress, following complaints against him.
After his reply was not found to be satisfactory, a censure has been issued against him, EC officials said.
In the meantime, the full bench of the Election Commission held a meeting to review the poll preparedness for the second phase of West Bengal Assembly polls on April 17.
The meeting, held through video conferencing, was attended by the observers, nodal officers of both state police forces and central armed police force and West Bengal's Chief Electoral Officer Sunil Gupta.