In a keenly watched outcome, counting of votes in the by-elections to one Assembly constituency each in Tamil Nadu and Puducherry will be taken up on Thursday.
The bypoll to Tiruchirappalli West is the first poll exercise after the AIADMK came to power in the April elections.
AIADMK and its rival DMK, who dumped their allies, have slugged it out in the run up to the poll. The bypoll was necessitated by the death of AIADMK Minister Mariam Pitchai in a road accident.
DMK has fielded former minister K. N. Nehru who was arrested on land-grabbing charges but came out of jail on the eve of the poll. Mr. Nehru had lost to Pitchai in the Assembly polls.
AIADMK has nominated former legislator M. Paramjothi for the seat.
Besides deputing a team of over 20 ministers and MPs for election work, Ms. Jayalalithaa herself campaigned for her party nominee.
DMK supremo M. Karunanidhi and his son, M. K. Stalin, campaigned for Mr. Nehru.
In Puducherry, the bypoll was held for the Indira Nagar seat vacated by Chief Minister N. Rangasamy, being the second constituency won by him in the April polls.
The outcome of the poll would be crucial for the All India NR Congress, which with a strength of 15 in the 30-member Assembly, formed its government with the support of an Independent. With Mr. Rangasamy resigning one of his two seats, the party’s strength has come down to 14.
Ruling AINRC’s A Tamilselvane, nephew of Rangasamy, is pitted against Congress’ K Aroumougame and AIADMK nominee A Venkateswararan.