The Trinamool leader also questioned Mitra why did he not resign earlier.
"Somen Mitra's resignation will not harm the Trinamool Congress in any way. He is a sinking force in Bengal. He has enjoyed all benefits as a TMC MP. Whatever he said (about the party) has no basis," Bandopadhyay, also an MP, said.
"Mitra has won the last Lok Sabha election riding on the popularity of Mamata Banerjee. Let him win a seat in the coming general election," he said, when asked whether the Congress would be strengthened if Mitra rejoined his parent party.