NEW DELHI: In another setback for Trinamool Congress (TMC) supremo Mamata Banerjee, party MP Sushmita Dev has resigned from the Rajya Sabha, PTI reported citing sources on Wednesday.Her resignation comes shortly after the TMC MP met Assam chief minister Himanta Biswa Sarma, triggering speculation about her joining BJP.In her resignation letter, Sushmita wrote, “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 of the Rajya Sabha,” she added.Sushmita’s resignation from the Rajya Sabha came shortly after fellow TMC Rajya Sabha member Sukhendu Sekhar Ray also stepped down from the House.Ray, who had previously voiced concerns over the RG Kar hospital case during the Mamata Banerjee government’s tenure, made a series of sharp allegations after quitting the party. The former TMC leader described his erstwhile party as a “party of thieves, rapists” and claimed he could have been “murdered by contract killers” had he resigned during the RG Kar controversy.The developments come at a difficult time for the Mamata Banerjee-led party, which is facing growing internal dissent following its defeat in the West Bengal assembly elections.Speculation about a rebellion within the TMC has intensified, with reports suggesting that around 20 Lok Sabha MPs are seeking to break away and function as a separate group.Rebel TMC MP Kakoli Ghosh Dastidar confirmed to ANI that a group of 20 MPs has formally approached the Lok Sabha Speaker seeking separate seating arrangements.“We are 20 MPs who have requested the Speaker for separate seating, and we will be working in conjunction with the Central and State Government for the development of West Bengal,” she said.The rebel MPs’ meetings with Union minister Bhupender Yadav and senior BJP leader Suvendu Adhikari have further fuelled speculation that the faction could eventually align with or merge into the NDA.