Three former Rajya Sabha members of the Trinamool Congress (TMC) resigned from the party and joined the Bharatiya Janata Party (BJP) in June 2026 [1].

The departures of Sushmita Dev, Sukhendu Sekhar Roy, and Prakash Chik Baraik signal deepening internal turmoil within the TMC. This shift occurs as a faction of the party openly challenges the leadership of Mamata Banerjee (TMC), the party's founder and longtime leader [1], [2].

These resignations follow a period of instability that intensified throughout June 2026. Reports indicate that approximately 19 to 20 TMC Lok Sabha MPs signed a letter stating that the "real TMC" is led by Kakoli Ghosh Dastidar rather than Banerjee [3]. This internal rift has created a public perception of a leadership crisis within the West Bengal-based party [2].

Legal pressures have further complicated the political landscape. Dr. Baidyanath Ghosh Dastidar, the son of Kakoli Ghosh Dastidar, filed one lawsuit against Mamata Banerjee [2]. The legal action coincides with claims from dissenting members that the official party structure no longer reflects the will of its representatives.

In response to these challenges, the TMC filed a fresh leadership list with the Election Commission. This filing was intended to affirm that official leadership remains under Mamata Banerjee, despite the claims made by the dissenting faction [4].

The BJP has leveraged these developments to suggest that Banerjee's grip on the party is weakening. The party said documents support the claim that the legitimate leadership of the TMC has shifted toward Dastidar [4]. While the TMC continues to operate under Banerjee's official designation, the loss of three senior former legislators to the opposition represents a significant blow to party unity [1], [3].

“Three former Rajya Sabha members of the Trinamool Congress (TMC) resigned from the party and joined the Bharatiya Janata Party (BJP)”

The defection of senior leaders to the BJP, combined with a coordinated challenge from nearly 20 Lok Sabha MPs, suggests a systemic fracture within the TMC. By attempting to redefine the 'real' party leadership through both legal filings and letters of dissent, the opposition is attempting to delegitimize Mamata Banerjee's authority. The outcome of the Election Commission's review of the leadership list will likely determine whether the TMC remains a unified entity or splits into rival factions.