Samajwadi Party patriarch Mulayam Singh Yadav files nomination for Mainpuri Lok Sabha constituency: Mulayam Singh Yadav had won from Mainpuri in 2014 Lok Sabha elections. He filed his nomination papers today from the same seat after a gap of 23 years. SP president Akhilesh Yadav and party leader Ram Gopal Yadav accompanied Mulayam Singh during the filing of the nomination, reports said.