Just over 17 million Sri Lankans are eligible to elect MPs to the 225-member parliament for a five-year term.Â
A record 690 political parties and independent groups are in the fray across 22 electoral districts.
The president, Marxist-leaning Anura Kumara Dissanayake, 55, was elected in September but his National People's Power (NPP) coalition had just three of parliament's 225 seats, prompting him to dissolve it and seek a fresh mandate.
Vote counting started soon after polling closed on Thursday, with results set for Friday.
Analysts say Dissanayake's coalition is expected to draw significant support, while a victory for a rival could lead to a policy logjam the country cannot afford.
A political outsider in a country dominated by family parties for decades, Dissanayake backs policies to fight poverty, such as bigger welfare measures, as well as battle graft.
Sri Lanka typically backs its president in general elections, especially if it is held soon after a presidential vote.
The president wields executive power but Dissanayake still requires a parliamentary majority to appoint a fully fledged cabinet and deliver on key election promises to cut taxes, support local businesses, and fight poverty.
The main challenger to Dissanayake's coalition is the Samagi Jana Balawegaya party of opposition leader Sajith Premadasa, who favours a mix of interventionist and free-market economic policies.
Also a key contender is the New Democratic Front, backed by previous President Ranil Wickremesinghe.
A nation of 22 million just across from the southern tip of India, Sri Lanka was crushed by a 2022 economic crisis triggered by a severe shortage of foreign currency that pushed it into a sovereign default and caused its economy to shrink.
Boosted by a $US2.9 billion ($A4.5 billion) bailout program from the International Monetary Fund, the economy has begun a tentative recovery, but the high cost of living is still a critical issue for many voters, especially the poor.
Dissanayake also aims to tweak targets set by the IMF to rein in income tax and free up funds to invest in welfare for the millions hit hardest by the crisis.
But investors worry his desire to revisit the terms of the IMF bailout could delay future disbursements, making it harder for Sri Lanka to hit a key primary surplus target of 2.3 per cent of GDP in 2025 set by the IMF.
"In past elections, people did not have confidence in us, but in September people gave us victory and proved that we are a winning party and we can form a government," Dissanayake said on Sunday near the end of campaigning.
"The next task is to unite people from the four corners of this country and build a powerful people's movement."
