Wickremesinghe faces a tough challenge from two formidable contenders. One is Anura Kumara Dissanayake, the leader of a once-marginal Marxist party tarnished by its violent past.
The party led two failed uprisings in the 1970s and 1980s that left more than 80,000 people dead, and it won less than four per cent of the vote in the previous parliamentary elections.
But Sri Lanka’s crisis has proven an opportunity for the 55-year-old Dissanayaka, who has seen a surge of support based on his pledge to change the island’s “corrupt” political culture.
He said at a polling station he was confident of securing the top job.
“After the victory, there should be no clashes, no violence,” he said. “Our country needs a new political culture.”
Fellow opposition leader Sajith Premadasa, 57, the son of a former president assassinated in 1993 during the country’s decades-long civil war, is also expected to make a strong showing.
Premadasa has vowed to fight endemic corruption, and both he and Dissanayaka have pledged to renegotiate the terms of the IMF rescue package.