Sitting BSP MLA Farid Mehfooz Kidwai, created a flutter in political circles on Monday when he joined the Samajwadi Party.
Mr Kidwai, who represents the Masauli Assembly segment in Barabanki district, is the first sitting BSP MLA to quit the party.
More than a dozen legislators belonging to the Opposition parties have joined the BSP in the past four years but the reverse trend began only on Monday.
Samajwadi sources said that four more Muslim MLAs and five Brahmin MLAs from the ruling BSP were in talks with the party leaders and will join them in the coming weeks.
Mr Kidwai, who joined the Samajwadi Party in the presence of party chief Mulayam Singh Yadav told reporters that he had been in touch with the Samajwadi leadership since the past one year.
“Don’t ask me why I left BSP? Ask others why they are still there,” he said in response to a query and added that he will resign from the Assembly seat soon.