More than half of the 2.53 lakh registered voters had cast their votes by 1 pm on Tuesday in the by-election to the Nuapada Assembly seat.
Chief Minister Mohan Charan Majhi, who visited Nuapada at least six times during the campaign, is treating the contest as a matter of prestige.
Polling began at 7 am across all 358 booths, including 47 marked as sensitive, under tight security measures.
