The dramatic development, just five days after the Bharatiya Janata Party (BJP) breached the Trinamool fortress, led to the saffron outfit taking control of three municipalities in the state from the ruling party.

Trinamool Congress-turned-BJP leader Mukul Roy's son Subhrangshu Roy, a two-term MLA from Bijpur constituency, Tushar Kanti Bhattacharya from Bishnupur (Trinamool) and Debendra Roy of Hemtabad (CPI-M) were the MLAs who joined the BJP at the party headquarters here.

So did more than 60 councillors from the municipalities of Kanchrapara, Halishahar and Naihati amid cries of "Bharat Mata ki Jai" and "Jai Shri Ram".

As a result, all three Municipalities will now be ruled by the BJP.

Vijayvargiya, the BJP in-charge of West Bengal and a party Genreal Secretary, asserted that more Trinamool Congress leaders would join the saffron party soon.

Vijayvargiya said: "We will do a seven-phase programme of joining, just like the state saw elections in seven phases."

He said that every month more and more people will join the BJP. "Those who feel suffocated in the TMC because of Mamata want to join the BJP."

But he said that the BJP will be selective. "Not everyone will be allowed (to join). Only those eligible will be allowed."

He said his best wishes were with Mamata Banerjee so that she remains the Chief Minister till 2021. "But if her 'karma' and people work like this, we cannot help."

Added Mukul Roy, once a right hand of Mamata Banerjee and now in the BJP: "The way Bengal is going under the leadership of Vijayvargiya, all the TMC people will join the BJP. From June 1 or 2, you will see the queue of MLAs."

The BJP stunned the Trinamool Congress by winning 18 of the 42 Lok Sabha seats -- from just two bagged in 2014.

The councillors who embraced the BJP included 17 each from Kanchrapara and Halishahar municipalities and 29 from Naihati municipality. Some panchayat heads also walked over to the BJP.

A despondent Trinamool Congress admitted there was a "minor crisis" in the party but vowed to bounce back in the 2021 Assembly elections.

"The Lok Sabha vote was not based on any people-centric issue. Polarisation and 'Chowkidar' were the issues. It is a minor crisis for our party. It has faced bigger crises. We will bounce back," West Bengal Minister of State for Parliamentary Affairs Tapas Roy said.

While campaigning in West Bengal, Prime Minister Narendra Modi had said that 40 MLAs from the Trinamool Congress were in touch with him.

Reacting to Modi's claim, Trinamool Congress leader Derek O' Brien had boasted: "Nobody will go with you. Not even one councillor."