Popular Bengali and Bollywood actor Mithun Chakraborty today joined the BJP, a little ahead of Prime Minister Narendra Modi's rally at the city's Brigade Parade Ground. The move comes weeks ahead of the state Assembly polls scheduled for March-April. The party's state in-charge Kailash Vijayavargiya had met up with the star yesterday at his residence in the state capital's Belgachia locality, sparking much speculation.