The announcement was made by Trinamool Congress vice president Mukul Roy, who said that TMC chairperson Mamata Banerjee has reconstituted the Punjab unit of the party and appointed former MP Brar as its ad hoc president with immediate effect.
In a tweet, Brar thanked Banerjee "for giving me this responsibility as part of our larger effort to forge a national alternative and work for grassroots".
Brar had been expelled by the Congress in April after his repeated public outbursts against former chief minister and state party chief Amarinder Singh.
Lok Hit Abhiyan convener Jagmeet Singh Brar had yesterday
More From This Section
met Mamata Banerjee on the sidelines of her protest against demonetisation in the national capital.
"I was in touch with Mamata for the past few months... I had extended my unconditional support to AAP in Punjab after due consultation with Mamata and my decision to join the TMC is also part of a larger initiative to build a National alternative," he said.
Brar clarified that "neither I nor any of my supporters had joined AAP - we had extended our complete support from the outside and had chosen not to join AAP formally to avoid any chance of confusion or insecurity among their cadre."
"With full authority at my command I am confirming that my supporters have joined the TMC with me and TMC will campaign and support AAP in 2017 assembly polls," he said.
Brar said leaders like Mamata Banerjee, Nitish Kumar, Arvind Kejriwal must come together to give country an alternative.