Bulgarian President Rumen Radev, a popular anti-corruption figure in the European Union's poorest country, scored a comfortable re-election victory on Sunday.

"Bulgaria is exiting from the deadlock," the former fighter pilot said after polling institutes estimated his share of the vote at 66 percent.

Bulgarians have voted "for change, for a break from corruption, from plunder and lawlessness, for a purging of the mafia from power," the 58-year-old said.

Anti-graft protests last year helped topple then premiuer Borisov, but his defeat failed to lead to a stable government
Anti-graft protests last year helped topple then premiuer Borisov, but his defeat failed to lead to a stable government AFP / NIKOLAY DOYCHINOV

Challenger Anastas Guerdjikov, credited with 32 percent of the vote, was quick to concede defeat, while asserting that "the entire apparatus of the state worked for the incumbent president".

Before Radev first assumed office in 2016, the presidency was largely ceremonial, but he transformed it, putting it at the heart of the struggle against corruption.

After casting his vote earlier Sunday, Radev said: "Let's take our destiny into our own hands, not let others undermine our future."

Sunday's vote was a run-off election after Radev missed an outright win in the first round last weekend, when he garnered 49 percent of the vote.

When President Rumen Radev gave a mandate to an anti-establishment party in April, he ended the 10-year rule of Boyko Borisov
When President Rumen Radev gave a mandate to an anti-establishment party in April, he ended the 10-year rule of Boyko Borisov AFP / Nikolay DOYCHINOV

Gerdjikov, also 58, won 23 percent.

Radev is the country's most popular politician, but Bulgaria itself is riven by fractious political parties. They have failed to deliver the stable government needed to tackle deep-seated graft and the worsening coronavirus pandemic.

"Everything's going wrong. I want that to change for my children, grandchildren and former pupils," retired teacher Dobrinka Nakova told AFP in the capital Sofia while out to vote.

Bulgaria's incumbent President Rumen Radev says he regrets not helping topple Boyko Borisov's regime sooner
Bulgaria's incumbent President Rumen Radev says he regrets not helping topple Boyko Borisov's regime sooner AFP / DIMITAR KYOSEMARLIEV

New Bulgarian University political science professor Antoniy Todorov described the vote as "a clash between two visions" in the eastern European country.

It is one between "the soft tolerance of endemic corruption and the firm opposition to a model of governance that uses public power for private purposes", he wrote in a recent blog post.

Voters quarantining at home with coronavirus can cast ballots at mobil polling stations
Voters quarantining at home with coronavirus can cast ballots at mobil polling stations AFP / Nikolay DOYCHINOV

Radev's clear win may usher in a period of political stability after a new anti-corruption party won a surprise victory last weekend in the country's third general election this year.

We Continue the Change is looking for coalition partners to end six months of political deadlock that have drawn out the worst political crisis since the end of communism three decades ago.

Gerdjikov, also 58, was backed by the GERB party of former conservative prime minister Boyko Borisov which came a close second in the general elections.

While many have praised Radev for sidelining Borisov, detractors have accused him of overreach.

His thumping victory may accentuate the "concentration of power", analyst Antony Galabov said in a television interview. "The president will have outsize influence."

Analysts had speculated that voter apathy might make the win more difficult for Radev, who was backed by the Socialists for his first five-year term but ran as an independent this time.

Only 40 percent of those eligible turned out for the first round, and the electoral commission said just 24 percent had voted by 1400 GMT on Sunday, down sharply from 2016.

Radev relied on a broad spectrum of supporters including We Continue the Change, whose founders -- Harvard graduates Kiril Petkov and Assen Vassilev -- served as ministers in the first interim administration Radev appointed in May after an inconclusive poll in April.

Radev had supported the protests against Borisov's 10-year rule last summer, shouting "Mafia out!" with his fist raised in the air as he briefly joined the crowd.

But the end of Borisov's reign also marked the beginning of the political deadlock.

And that has coincided with a coronavirus onslaught, Bulgaria having the lowest vaccination rate of any EU member and one of the world's highest Covid-19 mortality rates.

The second caretaker administration Radev appointed after parties failed yet another attempt to form a government after polls in July was strongly criticised for its poor handling of the outbreak.

The country has struggled to roll out jabs in the face of strong anti-vaccination sentiment and prolific fake news.