NEW DELHI: In another setback for the Trinamool Congress (TMC) supremo Mamata Banerjee, party MP Sushmita Dev has resigned from the Rajya Sabha, PTI reported citing sources.This comes shortly after the TMC MP met Assam chief minister Himanta Biswa Sarma, triggering speculation about her joining BJP.In her resignation letter, Dev wrote, “I do hereby resign from the membership of Rajya Sabha, which may please be accepted with immediate effect.”Sushmita’s resignation from the Rajya Sabha came days 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 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.His remarks come at a time when the Mamata Banerjee-led party is facing one of its toughest phases after 15 years in power in West Bengal, with a crushing electoral setback and growing dissent within its ranks in both the Assembly and Parliament.