BJP president Amit Shah is set to address a mega rally in West Bengal's Kolkata, amid a political war between his party and Mamata Banerjee's Trinamool Congress. The BJP aims to expand its footprints in the state, with an eye on 2019 Lok Sabha elections. Days ago, a war of words broke out between the BJP and Mamata Banerjee's party over the draft of Assam National Registrar of Citizens (NRC).