Ritabrata Banerjee Is Bengal LoP: How TMC Split, Explained

For 28 years, the Trinamool Congress was the one party in Indian politics that never cracked — built around a single leader, run on personal loyalty, and immune to the defections that hollowed out its rivals. That myth ended this week. Ritabrata Banerjee, a man the party expelled barely 48 hours earlier, walked into the West Bengal Assembly as the new Leader of Opposition, at the head of a rebel bloc claiming a clear majority of TMC's legislators. It is the first split in the party's history, and it has landed at the most vulnerable moment imaginable for Mamata Banerjee.

How Ritabrata Banerjee became Bengal's Leader of Opposition

The backdrop matters. In the 2026 Assembly election, the BJP swept Bengal in a landslide, winning 207 of 294 seats and forming the state's first right-wing government, with Suvendu Adhikari as Chief Minister. The TMC, which had ruled for 15 years and held 215 seats in the previous House, was cut down to just 80 — a stunning reversal that turned the party of government into the opposition overnight.

That shrunken number is exactly what made the rebellion possible. With only 80 MLAs, the official TMC's grip on its own legislature wing was thin. On 1 June 2026, the party expelled Ritabrata Banerjee and fellow MLA Sandipan Saha for alleged anti-party activities. Instead of fading away, the two turned the expulsion into a launchpad — and within days marched to the Speaker claiming the backing of a near two-thirds bloc of the party's legislators.

The anti-defection maths that made it legal

The move that looks audacious is actually a textbook use of a well-known loophole. Under India's anti-defection law (the Tenth Schedule), an individual MLA who defects normally loses their seat. But there is a crucial exception: if two-thirds of a legislature party split away as a group, none of them is disqualified.

For a party with 80 MLAs, that threshold works out to roughly 54 members. Ritabrata's faction claims 58 — comfortably across the line. That single fact is why the rebels are not facing disqualification and why the official TMC cannot simply have them thrown out. The numbers, if they hold up, give the breakaway group legal cover.

Here is the logic in plain terms:

• Below two-thirds: rebel MLAs risk losing their seats under anti-defection rules.
• At or above two-thirds: the split is protected, and the breakaway bloc can claim recognition as a separate legislature party.
• The result: with 58 of 80 on board, the rebels argue they are the real TMC legislature party — not a defection at all.

The final piece was the Speaker. Rathindra Bose, a first-time BJP MLA from Cooch Behar Dakshin who was elected Speaker of the 18th Assembly in May 2026, recognised the rebel group as the principal opposition and handed Ritabrata the Leader of Opposition's chamber. In a House where the Speaker decides such claims, that recognition is decisive — at least until it is challenged.

Who is Ritabrata Banerjee?

The man at the centre of all this is no newcomer to political turbulence. Ritabrata Banerjee was once a rising young face of the Left in Bengal, elected to the Rajya Sabha from the state in February 2014 as a CPI(M) member. His Left career ended abruptly in 2017, when the CPI(M) expelled him for anti-party activities following a television interview in which he criticised a senior leader.

After a spell in the political wilderness, he joined the TMC in 2020 and went on to win an Assembly seat. There is a certain irony that a politician twice expelled — first by the Left, now by the TMC — has emerged stronger each time. This week, the man cast out by Mamata's party is sitting in the chair reserved for her party's principal challenger.

Mamata's counter-move — and why it failed

The official TMC did not surrender the post quietly. Mamata Banerjee's camp nominated veteran leader Sobhandeb Chattopadhyay as its choice for Leader of Opposition, setting up a direct clash of claims before the Speaker. It was, in effect, an "Asli TMC" contest — two groups each insisting they represent the genuine party in the Assembly.

The Speaker's recognition of the rebels left Sobhandeb's nomination on paper only. For a leader who has dominated Bengal politics for a generation and is used to commanding total loyalty, being out-manoeuvred inside her own legislature party — in her own state — is a humiliation without precedent in her career.

The Abhishek Banerjee signal

What makes the rebellion politically sharper is how carefully it has been aimed. Ritabrata has gone out of his way to insist the revolt is not against Mamata Banerjee herself. The rebels have asked her to serve as the chief advisor of their legislature group — a gesture that keeps the door to the party's tallest figure open while seizing control of the bench.

The target, instead, is the party's number two. Ritabrata has declared that Abhishek Banerjee — Mamata's nephew, MP, and long seen as her heir apparent — will have "no role" in the rebel-controlled legislature wing. The rebels also allege that their signatures were forged on party documents, a grievance they cite as the trigger for the revolt. By separating Mamata from Abhishek, the rebellion frames itself as a fight against a younger power centre rather than against the founder — a classic strategy to peel away loyalists without forcing them to choose against their leader.

Why this matters and what comes next

A split is one thing; a split immediately after a crushing election defeat is another. The TMC is simultaneously absorbing the loss of power, the rise of a BJP government under Suvendu Adhikari, and now an internal revolt that has captured the very post — Leader of Opposition — meant to anchor its comeback. Control of that chair shapes who speaks for the opposition on the floor, who gets recognised in debates, and who is seen by the public as the alternative to the BJP.

Several things will decide how far this goes:

1. Do the numbers survive scrutiny? The 58-MLA claim is the rebellion's foundation. If even a handful drift back, the legal protection weakens.
2. Will the official TMC go to court? Speaker decisions on splits and defections are routinely challenged before the courts, and a long legal battle is likely.
3. Can Mamata reassert control of the organisation? She still holds the party machinery and the symbol — the rift, for now, is confined to the Assembly.
4. Does the BJP benefit? A divided opposition suits the new ruling party, and the Speaker's recognition of the rebels has not gone unnoticed.

What is certain is that the aura of an unbreakable Trinamool is gone. The party that survived every storm of Bengal politics for nearly three decades has, for the first time, split down the middle — and the person holding the opposition's chair is a man it expelled days ago.