Even the former Congress chief minister of Tripura, Sudhir Ranjan Majumdar, along with a number of front-ranking Congress leaders of the state also joined Trinamool Congress to float the Tripura wing of the party.

In his crossover to Trinamool Congress, Mukherjee was accompanied by state Intuc general secretary Samar Chakraborty and Calcutta Municipal Corporation's Congress councillor Dipali Das.

This is expected to snowball into an exodus from the West Bengal Pradesh Congress. Mukherjee's move packed a lot of theatrical punches in the event that unfolded at Banerjee's residence on Tuesday. And hordes of supporters converged on her residence to witness this "historic moment".

On Tuesday, Trinamool Congress alsofloated its first unit in Tripura. Like the West Bengal unit, the Tripura wing will also enter into an alliance with the Bharatiya Janata Party. Sudhir Ranjan Mazumdar will contest the polls from one of the two Lok Sabha seats of the state. Prior to this development, BJP was scheduled to field its candidates in these two Lok Sabha constituencies. However, at the insistence of Mamata Banerjee, BJP has ceded one seat to Mazumdar.

Subrata Mukherjee cocked a snook at the "spineless" Congress leadership because of its inability to take any action against him despite his recent statements supporting Trinamool Congress and its leader Mamata Banerjee. "The leadership is totally spineless. It could not take any action against me," he said.

Sources said West Bengal Pradesh Congress Committee (WBPCC) is trying to invoke the Anti-Defection Act to teach Mukherjee a good lesson. "The state leaders do not want to take away Mukherjee's party membership. Instead they want to cancel his membership of the state legislativeassembly. Abdul Mannan and Gyan Singh Sohanpal, two Congress MLAs, have already approached the state assembly speaker Hasim Abdul Halim on the issue," sources added.

Reacting to the Congress move to invoke Anti-Defection Act against him, Mukherjee said: "The speaker can act only when a member votes against his party whip inside the assembly. Outside the assembly he has no jurisdiction."