Premadasa, 57, studied at the London School of Economics and entered politics after his father, Ranasinghe Premadasa, was killed in a suicide bombing during a May Day rally in 1993.
He entered parliament in 2000 and later served as Sri Lanka's deputy health minister. In 2018, he was appointed minister of housing construction and cultural affairs.
The following year, Premadasa made his first run for the presidency. He gained 42% of the votes to finish second behind Gotabaya Rajapaksa, who fled the country in 2022 and later resigned amid widespread protests triggered by an economic meltdown.
Premadasa favours a mix of interventionist and free-market economic policies and currently leads the Samagi Jana Balawegaya (SJB) party that broke with President Ranil Wickremesinghe's United National Party (UNP) in 2020.
In the general elections that followed in August the same year, the SJB won 54 seats to become the main opposition to Rajapaksa's party, which won a overwhelming majority in the 225-seat parliament.
His centrist, more Left-leaning party has called for changes to the $2.9 billion bailout programme with the International Monetary Fund and his manifesto outlined plans to adjust some targets, such as changing taxes to reduce the cost of living.
"His policy outlines a comprehensive range of reforms and empowerment initiatives across various sectors," said a report by The Oslo Institute of Political Research and Advocacy.
"Notably, this policy statement is distinguished by its detailed presentation of facts and figures, enhancing its credibility compared to other policy statements."
There are 38 candidates for the presidency but Premadasa, alongside Wickremesinghe and Marxist-leaning Anura Kumara Dissanayake, are the three frontrunners, analysts say.
The Sri Lanka Opinion Tracker Survey by Institute for Health Policy (IHP) shows Premadasa coming in second in voting preferences at 32%, trailing Dissanayake at 36%, followed by Wickremesinghe who is third with 28%.
Premadasa is popular among the island's Tamil and Muslim minorities, who feel marginalised under previous governments which drew support from the majority Sinhala Buddhists.
"Ranil shrunk the economy, and people are suffering without even four square meals," Premadasa said on the final day of campaigning this week.
"Some have lost their livelihoods, and there’s no one to represent them. We will build a new, clean government of the people and restore the dignity of all Sri Lankans," he said.
