A day after quitting as MLA, Suvendu Adhikari on Thursday resigned from the primary membership of the TMC, intensifying speculations that he might switch over to the BJP later this week.
According to party sources, several disgruntled leaders are rallying behind him.
Adhikari, the face of the Nandigram movement that added to the political heft of Mamata Banerjee and catapulted her to power in Bengal in 2011, sent his resignation letter to West Bengal Chief Minister and TMC supremo Mamata Banerjee during the second half of the day, party sources said.
"I am writing to tender my resignation as a member of All India Trinamool Congress as well as from all other positions held by me in the party and its associate organs with immediate effect," Adhikari wrote.
Ending his two-decade-old association with the party, the former TMC heavyweight thanked Banerjee for the opportunities given to him, and said he would always value the time he spent as its member.
Some of Adhikari's supporters indicated that he was likely to join the BJP on Saturday during a saffron party programme in Midnapore. Union Home Minister Amit Shah, who is scheduled to visit Bengal for two days, starting Saturday, will also attend the programme.
Adhikari's resignation from the TMC puts a lid on all rumour mills that went abuzz speculating his moves since November 26, when he resigned as the chairman of Hooghly River Bridge Commissioners (HRBC).
Shortly after, he quit the state cabinet.
On Wednesday, he submitted his resignation as MLA of Nandigram constituency in Purba Medinipur district.
Of late, he had criticised the TMC leadership, on several occasions, for its style of functioning. The party made several attempts to woo him back, but none bore fruit.
Hinting that a rebellion was brewing in the ruling party ahead of the assembly polls, Adhikari had on Wednesday night held a closed-door meeting with its disgruntled leaders, including Asansol civic body chief Jitendra Tiwari and senior MP Sunil Mandal, in Paschim Bardhaman district.
Tiwari, an MLA from Pandebeshwar constituency who recently slammed the state government for allegedly depriving the industrial town of central funds for "political reasons", resigned as the chairman of the Board of Administrators, Asansol Municipal Corporation, on Thursday afternoon.
Senior TMC leader Diptangshu Choudhary, who, too, was present at the meeting, has also tendered his resignation from the post of South Bengal State Transport Corporation chairman.
Hailing Adhikari's decision, BJP national vice president Mukul Roy claimed that "this is the beginning of the end of the ruling party which would now collapse like a house of cards".
He asserted that the saffron party would welcome him with open arms. "The day Suvendu Adhikari resigned from the state cabinet, I had said I would be happy if he leaves the TMC and joins the BJP. Today, he has left the party. We would be happy to welcome him," Roy said.
Adhikari's father Sisir Adhikari and brother Dibyendu are sitting TMC MPs from Tamluk and Kanthi Lok Sabha constituencies respectively.
The family wields considerable influence over at least 40-45 assembly segments in Paschim Medinipur, Bankura, Purulia, Jhargram, parts of Birbhum -- mainly in the Junglemahal region -- and some areas in minority-dominated Murshidabad district.
With Assembly polls slated to held in April-May, the growing dissent within the TMC, if not reined in, might hamper the party's poll prospects.