Projections from polling agencies put his Progressive Bulgaria grouping at some 44 percent, which would give him an absolute majority of at least 129 seats in the 240-seat parliament.
The European Union’s poorest member has seen successive governments since 2021, when anti-graft rallies brought down the conservative administration of pro-European leader Boyko Borissov.
Radev, 62, who resigned earlier this year after nine years as president, ran on a pledge to fight corruption.
PB came in well ahead of Borissov’s GERB party and the liberal PP-DB coalition, both of which stood at around 12 percent, according to the projections.
Official final results are expected no earlier than Monday.
“PB has won unequivocally – a victory of hope over distrust, a victory of freedom over fear,” Radev told reporters outside his group’s office in Sofia.
He said Bulgaria would “make every effort to continue on its European path”.
“But believe me, a strong Bulgaria and a strong Europe need critical thinking and pragmatism. Europe has fallen victim to its own ambition to be a moral leader in a world with new rules,” the former air force general added.
Radev has said he wants to rid the Balkan nation of 6.5 million people of its “oligarchic governance model”.
He backed anti-corruption protests last year that brought down the latest conservative-backed government.
Radev has emerged as an “unequivocal winner,” Boryana Dimitrova of the Alpha Research polling agency told AFP.
Borissov, who headed the country virtually uninterrupted for close to a decade, congratulated Radev earlier on Sunday but insisted that “winning elections is one thing, governing is another.”
Borissov, 65, has dismissed claims that Radev brings something “new”, while highlighting his own party’s “extremely pro-European position,” including support for Ukraine and the EU.
Radev, on the other hand, has called for “practical relations with Russia, based on mutual respect and equal treatment”.
He has criticised a 10-year defence agreement signed last month between Bulgaria and Ukraine, which has been battling Russia since 2022.
He has also opposed Bulgaria sending arms to Ukraine, though he has said he would not use his country’s veto to block EU decisions.
Turnout exceeded 50 percent, the highest since April 2021, Dobromir Zhivkov, director of the Market Links agency, told AFP.
Participation had fallen to just 39 percent in the 2024 elections amid widespread public distrust in politics.
“Everything simply has to change,” Stiliana Andonova, a retired engineer, said after casting her ballot in Sofia, citing concerns over corruption and the judiciary.
Political parties had urged Bulgarians to vote in order to curb the impact of vote buying.
In recent weeks, police have seized more than one million euros in raids against vote buying and detained hundreds of people, including local councillors and mayors. (AFP)
