The third BJP Minister Dara Singh Chauhan, who had resigned from the Yogi Adityanath government last week, joined the Samajwadi Party on Sunday.
Apna Dal MLA Dr R.K. Varma also joined the party on Sunday.
Both the leaders and their supporters had quit the BJP after Swami Prasad Maurya resigned.
Speaking on the occasion, SP Chief Akhilesh Yadav urged the leaders to ensure that the BJP candidates forfeit their deposits in their constituencies.
He said, "The BJP has been practicing negative politics, promoting hatred and creating divisions. We will pursue the politics of development."
Akhilesh also slammed 'fake surveys' being published and added that the ground reality was much different to what was being portrayed.
He also announced that when his party comes to power, he will order caste census without delay.