"Sometimes in over excitement some party leaders and comrades use words which should not be used. Please don't make such comments against rival politicians and never make personal attacks on other politicians. We the Left leaders and workers should never do it," Bose said in a rally in the city.
Bose's comment came in the backdrop of reported derogatory comments made by former minister and CPI(M) MLA Anishur Rehman against West Bengal Chief Minister Mamata Banerjee months back.
Some politicians from both the ruling Trinamool Congress and Opposition (CPI-M) in Bengal are engaged in sharp exchange of words and personal mud slinging.