Kalyan Singh, who was Uttar Pradesh chief minister when the mosque at the disputed Ram Janmabhoomi-Babri Masjid site in Ayodhya was demolished, rejoined the BJP at the party office here.
The poll panel had on Monday concluded that Singh's remarks supporting the return of Narendra Modi as prime minister are violative of the model code and is learnt to have written to President Kovind flagging the issue.