Poonam Sinha, wife of an actor turned politician Shatrughan Sinha, filed her nomination from Lucknow Parliamentary Constituency on Thursday, two days after she joined the Samajwadi Party. Sinha, an SP, BSP, RLD candidate from Lucknow, is pitted against Union Minister Rajnath Singh in the constituency. Rajnath had won from Lucknow in the 2014 general elections. SP, BSP, RLD are contesting Lok Sabha polls in alliance in Uttar Pradesh in which the SP will contest on 37 seats, BSP on 38 and RLD on three.