The resignations triggered Rajya Sabha bypolls as the BJP seeks to win all three vacant seats, party officials said.
On Thursday, former Trinamool Congress Rajya Sabha MPs Sushmita Dev, Sukhendu Sekhar Ray, and Prakash Chik Baraik joined the Bharatiya Janata Party in Kolkata, weeks after resigning from the Upper House and quitting the Mamata Banerjee-led party.
The leaders cited the "mandate" delivered by West Bengal voters as a "turning point" for their departures, citing corruption concerns weeks after the party faced defeat in the Assembly elections.
Representing West Bengal in the Rajya Sabha since 2011, Ray served as the party's chief whip. Dev joined the TMC in 2021, while Baraik entered the Upper House in 2023.
The Election Commission announced bypolls for the three vacant Rajya Sabha seats. With a majority in the West Bengal Assembly, the BJP now aims to secure all three positions.
Nominations for the three vacant seats must be filed by July 14. BJP state president Samik Bhattacharya attended the induction ceremony, as the party weighs nominating the leaders to the Rajya Sabha.