Sovan Chatterjee has switched over to the BJP from Trinamool Congress.

A section of the BJP in West Bengal is apprehensive that the party's anti-corruption crusade might take a beating ahead of the next assembly election in the state following TMC leader and Narada scam accused, Sovan Chatterjee, joining it.

Although a section of the state BJP leaders had heaped praise on Mr Chatterjee for his organisational skills, they were apprehensive about the role he would have in the party. Mr Chatterjee, a four time MLA of TMC and two time mayor of Kolkata Municipal Corporation besides being a minister, had switched over to the BJP on August 14.

"The induction of Sovan Chatterjee in BJP may have more adverse effect than do good to the party as it will blunt our anti-corruption crusade against the Mamata Banerjee government. He is one of the accused in the Narada scam. The scam has been one of our poll planks in the Lok Sabha polls," said a senior state BJP leader, who did not want to be named.

Mr Chatterjee, who was a close lieutenant of Ms Banerjee, had been asked by her to resign from his post as both minister and mayor in November last year following problems in his personal life. Since then he had taken sabbatical from politics and his joining BJP had taken TMC by surprise.

"It is true that we need to send out a message that TMC leadership is slowly but steadily losing ground in Bengal. So there has to be exodus of TMC leaders to BJP. But at the same time the party should be careful before taking a call on leaders, who have corruption charges against them," said another state BJP leader.

The BJP has made deep inroads in Bengal in the last Lok Sabha polls as it won 18 of the 42 Lok Sabha seats in the state.

According to state BJP sources, the party faced repeated embarrassment over TMC councillors who joined it post Lok Sabha elections but reverted to their original party within a month. It had also not gone down well with the party central leadership.

When asked to comment on allegations of corruption against Mr Chatterjee, state BJP president Dilip Ghosh said those have not been proved. "Allegations against him (Sovan Chatterjee) are not proved. If it is proved then the party will take a call accordingly. And you must remember one thing - TMC is a party which supports corruption and BJP fights corruption," Mr Ghosh said.

Opposition CPI(M) and Congress have alleged that Mr Chatterjee has switched to BJP to evade CBI in Narada scam. The allegation has been denied by both Mr Chatterjee and the BJP.

"My joining the BJP has nothing to do with the investigation in the Narada scam. I have joined BJP as I am disillusioned with the functioning of TMC," Mr Chatterjee said.