Voting for the Milkipur by-election in Uttar Pradesh's Ayodhya district began on Wednesday morning.
The voting in the constituency started at 7 am and will continue until 5 pm.
The fate of candidates in the fray will be decided by the Scheduled Castes (SC)-reserved constituency's 3,70,829 voters but the main contest is expected to be between Samajwadi Party's Ajit Prasad and the BJP's Chandrabhanu Paswan.
The by-election neccesiated after Samajwadi Party MP Awadhesh Prasad vacated the seat after winning the Lok Sabha election from Faizabad (Ayodhya) held last year.