Shivpal Yadav is still a Samajwadi Party legislator from Jaswant Nagar seat in Etawah district.
Weeks after launching his front, Samajwadi Secular Morcha (SSM), Shivpal Singh Yadav on Tuesday announced his new political party, Pragatisheel Samajwadi Party Lohia (PSPL).
"Our new party has been registered (with the Election Commission). It's name is Pragatisheel Samajwadi Party Lohia," Mr Yadav said at a membership programme of the SSM in Lucknow.
Speaking about the Samajwadi Party, he said he always wanted "unity" in the party but was forced to leave due to "sycophants".
However, he is still a SP legislator from Jaswant Nagar seat in Etawah district.
At the programme organised by Mr Yadav's supporters, his aide and former minister Sharda Pratap Shukla said the PSPL will become a big force in the state.
Mr Yadav launched the SSM on August 29 after he fell out with his nephew and Samajwadi Party (SP) president Akhilesh Yadav.
At the launch of his front in August, Mr Yadav had said he felt neglected in the SP, which was founded by his elder brother Mulayam Singh Yadav, after his nephew took charge of the party.
Earlier, Mr Yadav had announced that his front will contest all 80 Lok Sabha seats in the 2019 general elections.