How Mamata Banerjee's 15-Year Grip on TMC Unravelled in Just 35 Days, From Poll Defeat to an Open Revolt by MLAs and MPs

The results of the West Bengal Assembly elections were not the only setback for Mamata Banerjee’s Trinamool Congress (TMC). In the weeks following the party’s unexpected defeat, the TMC has been hit by a series of political crises that have raised serious questions about its future.

The biggest blow came on Monday when at least 20 dissident TMC MPs reportedly submitted a letter to Lok Sabha Speaker Om Birla expressing their desire to join the National Democratic Alliance (NDA). The development came just hours after Rajya Sabha MP Sukhendu Shekhar Ray resigned from the party.

More than a routine political setback, the latest developments mark one of the most significant challenges to Mamata Banerjee’s leadership in over a decade. With more than two-thirds of the party’s MLAs already in open rebellion, the unrest among MPs has further weakened her authority and sparked fresh debate over her political future. 

How This All Started

The erosion of Mamata Banerjee’s influence within the TMC has emerged as one of the most dramatic political developments in West Bengal following the BJP’s sweeping victory in the 2026 Assembly elections. Mamata Banerjee herself suffered a major personal setback after losing the Bhabanipur seat to Suvendu Adhikari, her former aide who later became Chief Minister.

Soon after the BJP secured 207 seats in the 294-member Assembly on May 4, signs of unrest began surfacing within the TMC. Several leaders, including Manoj Tiwary, Arunava Sen, Papiya Ghosh and Kakoli Ghosh Dastidar, publicly voiced dissatisfaction with the party leadership and what they described as the high-handed functioning of TMC general secretary Abhishek Banerjee. The favouritism towards Abhishek Banerjee and sidelining the senior leaders became the main reason for the decline. 

The leaders pointed to deep-rooted corruption within the organisation and accused the top leadership of being disconnected from public sentiment and governance concerns. Their criticism would soon evolve into a larger challenge for the party.

Resignations, Boycotts and Expulsions

What began as internal criticism gradually developed into a broader revolt against the party leadership. Former TMC MP Santanu Sen stepped down as the party spokesperson, while Kakoli Ghosh Dastidar resigned from all organisational posts. More than 100 municipal councillors also quit their positions, indicating growing discontent across different levels of the party.

A major indication of Mamata Banerjee’s declining control emerged on May 30, when 60 of the party’s 80 MLAs skipped a meeting convened at her Kalighat residence. Although the TMC linked the absence to recent attacks on party leaders, the incident highlighted widening trust deficits within the organisation.

The crisis deepened further on June 2 when MLAs Ritabrata Banerjee and Sandipan Saha were expelled over alleged anti-party activities. The two legislators had approached the Assembly Speaker, alleging that signatures of several MLAs had been used without consent on a letter supporting the party’s preferred Leader of the Opposition, Sobhandeb Chattopadhyay. The complaint subsequently led to a police inquiry.

Ritabrata Banerjee Emerges as Face of Assembly Revolt

A month after the election defeat, Mamata Banerjee faced another major setback when 58 of the TMC’s 80 MLAs submitted a letter to the Assembly Speaker supporting Ritabrata Banerjee as Leader of the Opposition. The Speaker accepted the claim and formally recognised Ritabrata Banerjee as the LoP, effectively taking control of the party’s legislature wing away from Mamata Banerjee’s faction.

The episode marked a striking reversal for a leader who had dominated West Bengal politics for 15 years. It was particularly significant because the challenge came from an MLA who had joined the party only six years ago. Since assuming the role, Ritabrata Banerjee has repeatedly targeted Abhishek Banerjee, accusing him of corruption, encouraging dynastic politics and contributing to the party’s electoral defeat.

This is just like when Eknath Shinde led a rebellion within the Shiv Sena, splitting the party and successfully claiming its name and logo.

Rebellion Reaches Parliament

The TMC’s internal crisis has now extended beyond West Bengal and into Parliament. Kakoli Ghosh Dastidar has emerged as one of the leading voices of the rebellion in the Lok Sabha, claiming that 20 MPs have written to Speaker Om Birla seeking permission to join the NDA.

While Mamata Banerjee, Abhishek Banerjee and other senior leaders attended the INDIA bloc meeting at the Constitution Club, rebel MPs reportedly gathered at the Motilal Nehru Marg residence of Union Minister Bhupender Yadav, who served as the BJP’s West Bengal election in-charge.

Uncertain Road Ahead for TMC

In just over a month, Mamata Banerjee has gone from being West Bengal’s dominant political figure to confronting the most serious internal challenge of her political career. The sequence of events, from criticism and resignations to a full-scale rebellion among legislators and MPs, has intensified speculation about the future of the Trinamool Congress and the Banerjee family’s grip on the party.

For the TMC, one positive sign remains that several rebel MLAs continue to recognise Mamata Banerjee as the party’s supreme leader, suggesting that her personal influence still carries weight within sections of the organisation. Whether that remaining goodwill will be enough to help her regain authority, however, remains uncertain.
 

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