The battle for Bengal's 42 seats is proving one of the toughest this election, with the BJP aiming for 23 seats and chief minister Mamata Banerjee determined not to cede any. This is the most polarised election the state has seen, where the bulk of sparring has been between Prime Minister Narendra Modi and Mamata Banerjee. The BJP, however, has left nothing to chance. Party chief Amit Shah and Uttar Pradesh Chief Minister Yogi Adityanath have also campaigned regularly in the state.