Voters in Bulgaria are heading to the polls in the eighth election in five years on Sunday with ex-president Rumen Radev's grouping expected to win on a pledge to fight corruption.

The European Union's poorest member has been mired in a political crisis since 2021 when large anti-corruption rallies toppled the conservative government of long-time leader Boyko Borissov.

Radev, a former airforce general who has advocated for renewing ties with Russia and slammed sending military aid to Ukraine, was president for nine years.

He stepped down earlier this year to lead newly formed centre-left grouping Progressive Bulgaria, with opinion polls before Sunday's vote suggesting the bloc could gain 35 percent of the vote.

Radev has said he wants to rid the country of its "oligarchic governance model" and backed anti-corruption protests in late 2025 that brought down the conservative-backed government.

"Radev's cause is for Bulgaria to have a future.

We have reached a point where we are questioning the very future of our own country," Lazar Lazarov, a 28-year-old philosophy teacher, told AFP at Radev's final campaign rally in Sofia earlier this week.

"Radev has proven himself as president and as a statesman.

He's the one who is most acceptable for the EU, the United States, Russia and, if you like, even for China." Borissov's pro-European GERB party is likely to come second, according to opinion polls, with around 20 percent, ahead of the liberal PP-DB.

Polling stations will open at 0400 GMT and close at 1700 GMT.

- 'At ease!' - Radev has slammed the EU's green energy policy, which he considers naive "in a world without rules", as well as any Bulgarian efforts to send arms to Ukraine battling a Russian invasion since 2022.

Turnout in Sunday's snap election in....