The CPI-M leadership and West Bengal Governor M K Narayanan are at loggerheads over the issue of the spiral of violence that hit Kolkata after the attack on state finance minister Amit Mitra and the heckling of Mamata Banerjee.

Expressing shock over the 'premeditated assault' on West Bengal Chief Minister Mamata Banerjee, Mitra and other senior State Ministers in New Delhi, Governor M K Narayanan said on Wednesday that the incident was 'serious enough to warrant a public apology' by the Politburo of the Communist Party of India (Marxist).

Communist Party of India state chief Biman Bose responded that the governor probably did not even know what politburo is. To this, Narayanan retorted, "I have been studying communism for the last 60 years."