Sri Lanka's new leftist leader has drawn strong support from an unlikely source as he seeks to expand his three parliamentary seats to a house majority in elections on Thursday.

President Anura Kumara Dissanayake, 55, who counts Karl Marx and Che Guevara among his heroes, has the backing of the country's largest and most influential private sector trade and industry body.

Dissanayake took power in September on the back of public anger over the island's 2022 economic meltdown — and the Ceylon Chamber of Commerce (CCC) has said its proposals for economic recovery match the socialist agenda of his People's Liberation Front (JVP).