Sovan Chatterjee, who has switched over to BJP from Trinamool Congress, on Saturday criticised TMC no longer being a party of old timers and for deviating from the principles of parliamentary democracy.
Mr Chatterjee, who was once the trusted aide of TMC supremo Mamata Banerjee, said that since joining BJP he has been afraid about his security.
Reacting to his allegations, TMC secretary general Partha Chatterjee said Sovan is trying to give "lame excuses".
Partha Chatterjee along with his friend Baishaki Banerjee, who was a leader of TMC's education cell had joined BJP in Delhi on August 14. TMC is yet to officially expel him.
"There is no place for old timers in TMC," said the former Kolkata mayor and state minister.
"We all had worked together to take TMC to the place where it is now, while fighting against the Left misrule. But now things have changed, the old timers are being humiliated. If you raise your voice against misdeeds of the party then you are either sidelined or shunted out," Mr Chatterjee told a Bengali news channel.
Mr Chatterjee while joining the BJP at its headquarters in Delhi had criticised the "violence and undemocratic atmosphere" in which the 2018 panchayat polls were conducted in the state.
"We had fought against the violence and undemocratic way of the Left Front government. But unfortunately the TMC government too is functioning in the same way. I raised the issue with party supremo and West Bengal Chief Minister Mamata Banerjee but it didn't bear any result," he said.
Partha Chatterjee hit back saying "Everybody knows the role Mamata Banerjee had played in shaping his (Sovan Chatterjee's) political career. He may have forgotten that and now is giving lame excuses. The people of Bengal won't forgive him".
Sovan Chatterjee had been the two time mayor of Kolkata, four time MLA of the TMC and a minister.
Mr Banerjee had played a key role in shaping his political career, which like her had begun as a Youth Congress activist.
After the party's stupendous victory in the 2016 assembly polls, Chatterjee, who was then the Kolkata mayor, was rewarded the most and given the charge of three crucial departments.
But due to problems in his personal life he was asked to step down both as minister and mayor by Banerjee herself in November last year. Since then he was on sabbatical from active politics, which he ended by joining the BJP.
Get Breaking news, live coverage, and Latest News from India and around the world on NDTV.com. Catch all the Live TV action on NDTV 24x7 and NDTV India. Like us on Facebook or follow us on Twitter and Instagram for latest news and live news updates.