New Delhi: The Election Commission on Tuesday issued notification for phase four of Lok Sabha elections to be held on April 29 in which 71 seats across nine states will go to polls. Uttar Pradesh, Bihar and West Bengal will head for voting in all the seven phases of the general elections. The election will pit the BJP-led National Democratic Alliance against mostly different opposition groupings in various states, including of Congress, the Left and regional forces which are continuing to work out a grand alliance to minimise a division of votes against the saffron party. The BJP has worked out a seat-sharing formula with some new allies and several old partners. However, opposition parties are yet to do so in several states.