Ripun Bora had been with the Congress since 1976
Former Assam Congress president Ripun Bora on Sunday joined the Trinamool Congress in the presence of party's national general secretary Abhishek Banerjee in Kolkata.
"It gives us immense joy to welcome Shri Ripun Bora, who joined the AITC family in the presence of our National General Secretary Shri @abhishekaitc," Trinamool Congress posted on Koo.
Mr Bora, as a joint candidate of the opposition parties in Assam, had unsuccessfully contested the recent Rajya Sabha election.
Mr Banerjee also welcomed him to the West Bengal's ruling party.
"Extending a very warm welcome to Shri @ripunbora, a stalwart and skilled politician, who joined the @AITCofficial family today. We are extremely pleased to have you onboard and look forward to working together for the well-being of our people!," he tweeted.
Mr Bora, who had been with the Congress since 1976, in his resignation letter to party chief Sonia Gandhi alleged that a section of Congress leaders in Assam have been in touch with the ruling BJP leaders and Chief Minister Himanta Biswa Sarma.