Voting for by-poll to the Erode East Assembly constituency commenced at 7 am on Wednesday, amid heavy police protection.
Polling will be held in 237 booths across 53 locations.
Owing to cold conditions, people did not turn up in big numbers at the start of the polling but more voters are expected later in the day, officials said.
A total of 46 candidatesāincluding 44 independents, are in the fray, although the battle is confined between the ruling DMK and actor-politician Seemanās Naam Tamilar Katchi (NTK).
The DMK has fielded former MLA V C Chandrakumar while M K Seethalakshmi is the NTKās pick. Main Opposition AIADMK and the BJP have announced boycotting the by-poll, necessitated due to the death of Congress MLA EVKS Elangovan last year.