“I’m resigning as a president of AAP Punjab… But my fight against drug mafia and all kind of corruption in Punjab will continue as an ‘Aam Aadmi’ (common man) of Punjab,” Mann tweeted.
His resignation comes a day after AAP convenor Arvind Kejriwal apologised to former Punjab minister Bikram Singh Majithia for alleging that he was involved in the “drug trade”.
Mann represents the Sangrur parliamentary constituency in the Lok Sabha remarks.
He was appointed the state party chief in May 2017.
Majithia had filed a defamation case against Kejriwal and others following the allegation made during campaigning in the Punjab Assembly elections .