TMC Crisis: How Mamata Could Lose Her Own Party, Explained

A month ago Mamata Banerjee was the chief minister of West Bengal. Today she is fighting to keep control of the party she built from scratch. The Trinamool Congress crisis that erupted this week — with crisis huddles at her Kalighat home, mass MLA no-shows and a rival claiming to be the 'real' TMC — is not an ordinary post-election sulk. It is the most serious internal challenge the party has faced since it was founded in 1998, and it is unfolding through a legal loophole that India has seen weaponised before.

Here is what is actually happening, why the numbers matter so much, and what could come next.

How a landslide defeat became a leadership crisis

The spark was the 2026 West Bengal Assembly election. Voting for all 294 seats happened across two phases in April, results came on 4 May, and the verdict was historic: the BJP won a landslide and formed a government in Bengal for the first time, ending roughly 15 years of TMC rule. Turnout was about 94%, among the highest ever recorded for an Indian election.

Defeats of that scale rarely stay quiet inside a party. Within weeks, grumbling about Mamata Banerjee's centralised, top-down style — and about the outsized role of her nephew Abhishek Banerjee — hardened into open revolt. When a leader can no longer hand out ministries and power, the glue that holds a personality-driven party together starts to dissolve.

The immediate flashpoint was procedural but explosive. The TMC's legislature party had to formally name its Leader of Opposition, a deputy leader and a chief whip in the new Assembly. Dissident MLAs alleged that signatures on the documents sent to the Assembly secretariat had been forged — a charge the leadership rejected. The state's CID is now reported to be investigating the signature row.

The revolt: empty chairs at Kalighat

The scale of the mutiny became visible when Mamata called her newly elected MLAs to her home for a strategy meeting. According to multiple reports, only around 20 of the roughly 80 summoned legislators turned up; the rest stayed away. The meeting was effectively abandoned, and Mamata alleged a BJP conspiracy to engineer defections.

The symbolism was brutal. A leader famous for commanding fierce personal loyalty was left looking at empty chairs in her own drawing room, a day after reported attacks on Abhishek Banerjee and senior MP Kalyan Banerjee added to the sense of a party in free fall.

The party responded the way cornered organisations do — with expulsions. It threw out two MLAs, Ritabrata Banerjee and Sandipan Saha, citing anti-party activity. But because the two had been the ones publicly flagging the alleged forged signatures, the expulsions looked to many like punishment for whistleblowing, and they handed the rebels a ready-made grievance.

Who is Ritabrata Banerjee?

The man now leading the charge against Mamata is a political shape-shifter. Ritabrata Banerjee started out on the Left, rising through the CPI(M)'s student wing SFI to become its all-India general secretary, and the party sent him to the Rajya Sabha in 2014. Estranged from the Communists, he crossed over to the TMC ecosystem, ran its trade union arm INTTUC, was seen as close to Abhishek Banerjee, got a Rajya Sabha berth again in 2024 and then an Assembly ticket — winning Uluberia Purba in 2026.

That journey matters. He knows how legislature parties, whips and the rulebook work, and he has now been named Leader of Opposition by the breakaway group. A man the Left once projected as its future, who later praised Mamata as the face of mass politics, is the face of the rebellion against her.

The real story: the two-thirds defection math

This is where the crisis stops being gossip and becomes constitutional chess. India's anti-defection law — the Tenth Schedule of the Constitution — normally disqualifies legislators who defy their party. But it carves out one big exception: if a large enough chunk of a legislature party breaks away, they cannot be disqualified.

The magic number is two-thirds. The rebels say they have the backing of around 58-59 of the TMC's MLAs, comfortably above the roughly 54 needed to clear the two-thirds bar in the party's legislature group. If that holds, the breakaway faction argues it — not Mamata's official leadership — is the genuine Trinamool.

• Below two-thirds: rebels risk disqualification and losing their seats.
• At or above two-thirds: they can claim legitimacy as the real legislature party and dodge the anti-defection axe.
• The catch: the exact count, and whether every claimed signature is genuine, is fiercely disputed — and the Assembly Speaker is the referee who certifies it.

If this template feels familiar, it should. It is the same playbook that split the Shiv Sena in Maharashtra, where a faction with the numbers walked away with the party and the government. Commentators are already calling the Bengal episode a kind of 'Operation Shinde', and the comparison is the rebels' best friend and Mamata's worst nightmare.

Beyond the MLAs: the organisation cracks too

A legislature split is dangerous; an organisational collapse is fatal. And there are signs the rot runs deeper than the Assembly. Reports describe more than 120 municipal councillors resigning, district-level leaders drifting, and at least one prominent figure attending a meeting hosted by new BJP chief minister Suvendu Adhikari.

The TMC leadership has tried to reassert control by dissolving several state committees and frontal organisations — a move meant to dismiss disloyal office-bearers and rebuild from scratch. Meanwhile Mamata has fallen back on the weapon that made her: street agitation, announcing a sit-in over alleged post-poll violence and attacks on TMC workers. It is a reminder that even cornered, she remains a formidable mass mobiliser who has clawed back from worse.

What comes next

The crisis is moving fast, and several battles will run in parallel:

1. The Speaker's ruling. Whether the breakaway group is recognised as a valid split, and whether any MLAs are disqualified, depends on the Speaker's verification of the numbers and signatures.
2. The forgery probe. The CID inquiry into the disputed signatures could shape who looks like the wronged party — and could cut either way.
3. The fight for the name and symbol. If both sides claim to be the real TMC, the dispute heads to the Election Commission, which decides who keeps the registered name and the twin-flowers symbol. That process can drag on for months.
4. Court challenges. Whatever the Speaker or EC decides, the losing side is almost certain to head to the high court or Supreme Court, as happened in Maharashtra.

For now, the story is bigger than one bad meeting. A defeated former chief minister is trying to hold together a party that several dozen of her own legislators may be walking out of, using a loophole built into the Constitution itself. Whether Mamata Banerjee re-establishes her grip or watches the TMC fracture into a Mamata faction and a Ritabrata faction will shape the opposition to the BJP in Bengal for years. As things stand, the only certainty is that the huddles at Kalighat are far from over.