In an another blow to TMC chief Mamata Banerjee, Trinamool Congress (TMC) Rajya Sabha MP Sushmita Dev has officially resigned from the Upper House (Rajya Sabha). Her resignation came on June 10, 2026, just days after TMC MP Sukhendu Sekhar Ray stepped down, marking the second major departure for the party in a single week.

Signs of dissent within the Trinamool Congress appear to be growing, posing a challenge to party chief Mamata Banerjee’s authority. After 61 MLAs reportedly backed rebel leader Ritabrata Banerjee, the unrest has now extended to the party’s parliamentary ranks.

Dev also met Assam CM Himanta Biswa Sarma in New Delhi on Wednesday morning. There is speculation that she may also join the BJP at a later stage.  

“I do hereby resign from the membership of Rajya Sabha, which may please be accepted with immediate effect. I convey my sincere gratitude to your Excellency, Hon’ble Deputy Chairman and all functionaries of the Rajya Sabha Secretariat extending all help and cooperation during my tenure as a Member ofthe Rajya Sabha,” she wrote in a letter.

Prior to her current role, she made headlines by resigning from the Congress party in 2021 after a nearly three-decade association to join the TMC. Her father the late Santosh Mohan Dev was a Union Minister in the UPA-1 government.

Formerly a Congress MP representing Silchar in Assam, Sushmita Dev parted ways with the party following her defeat in the 2019 Lok Sabha elections and joined the Trinamool Congress in 2021. She rapidly emerged as a prominent figure within the party, serving as its national spokesperson before being nominated to the Rajya Sabha. 

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The Trinamool Congress is grappling with the most severe internal turmoil in its nearly 30-year history, as rebellions have erupted simultaneously within its legislative and parliamentary ranks following the party’s defeat in the West Bengal Assembly elections.

The unrest has left party chief Mamata Banerjee struggling to maintain control over an organisation that was once seen as firmly united under her leadership.

The crisis first unfolded in the West Bengal Assembly, where a large section of TMC legislators broke away to form a separate faction led by expelled MLA Ritabrata Banerjee. Supported by 58 of the party’s 80 MLAs, the group secured recognition from the Speaker and emerged as the principal opposition bloc in the House. While distancing itself from the TMC’s central leadership, the faction has retained its opposition to the BJP, stating that it intends to pursue a “constructive opposition” agenda focused on Bengal’s development.

The turmoil intensified days later in New Delhi when a group of TMC Lok Sabha MPs, led by Kakoli Ghosh Dastidar , reportedly signalled support for the BJP-led National Democratic Alliance . The developments have raised fresh concerns about the party’s ideological unity and long-term political trajectory.

Amid the growing crisis, Mamata Banerjee has reached out to opposition allies for support. On Tuesday, she held a closed-door meeting with Sonia Gandhi to discuss strengthening opposition coordination and the future of the INDIA bloc .

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