Delhi legislator and BSP candidate Narayan Dutt Sharma, who was earlier with the AAP, was allegedly attacked with batons by three unidentified people in the early hours of Thursday, police said.
Sharma, who is the legislator from Badarpur and is seeking re-election to the Delhi assembly as a Bahujan Samaj Party candidate, received minor injuries.
"The attack on Narayan Dutt Sharma is condemnable and shameful," BSP chief Mayawati said on Twitter.
The incident took place around 1 am when he was returning to his home in Badarpur after a party meeting. Three men stopped his car and beat him up, a senior police official said.
The three accused are yet to be caught, he added.