Speaking on the occasion, Bajpai said that the party would be benefited with this ahead of the upcoming Panchayat and 2017 Assembly polls.
Singh, who was the state Minister for Rural Engineering Service (RES) department in the previous Mayawati regime had left BSP two days ago.
"I have resigned from BSP on July 24 as it had no concerns for woes of common man," he said here.
Meanwhile, Singh's son Atul and supporters also joined the party.