52-year-old Nafisa, who is in Lucknow, was seen campaigning alongside Congress state president Rita Bahuguna Joshi for party candidate from Lucknow (West) Assembly constituency, Shyam Kishore Shukla, for the byelections on November 7.
"Nafisa has joined Congress again. She was with the party earlier too," a senior party leader told PTI on Thursday.
The former Miss India had contested the parliamentary elections this year on an SP ticket, replacing Dutt, who was barred by the Supreme Court from contesting the polls.