The two along with MLA Vimlesh Singh joined the party in presence of SP supremo Mulayam Singh Yadav, state president Akhilesh Yadav, leader of opposition Shivpal Singh Yadav and senior leader Mohammad Azam Khan.
Anuradha Chowdhury, a former minister and once considered close to Ajit Singh, came down heavily on RLD chief for entering into an alliance with Congress, accusing him of going against the ideology of his father Chowdhury Charan Singh, who always fought against the party.
"Instead of entering in an alliance with Congress for getting ministerial berth, Ajit Singh should have fought for passage of land acquisition bill. His father has always fought in the interest of farmers against Congress," Chowdhury said.
"The RLD workers and leaders did not like the alliance. RLD will have to suffer due to this alliance (with Congress," Chowdhury said, adding that she would not contest elections but only campaign for SP.
Asked about the issue of reservation to Muslims, party leader Azam Khan said that Muslims were cheated in the name of reservation, which had been given to eight castes and the community would get on 0.8 per cent reservation, "which is meagre".
"Congress always cheated Muslims. Be it shilanyas in Ayodhya or demolition of Babri mosque, Congress always acted against the Muslim community," he said.
Asked whether SP would provide separate reservation to Muslims if voted to power, Khan said that it could only promise that reservation percentage would be better that in Andhra Pradesh and Kerala.
"We cannot promise about how much per cent reservation will be given to Muslims, but it will be better than that in AP and Kerala," he said.
About removal of officers in UP by EC, Khan said that the party would also complaint against Cabinet Secretary and press for his removal.
Welcoming the leaders into party fold, Mulayam said their presence would strengthen the SP. Bollywood actor Vishwajeet Pradhan and leaders of Rastriya Ulema Council also joined SP on the occasion.