Bulgarians are voting in the eighth parliamentary election in five years, with the clear frontrunner, the pro-Russian former president Rumen Radev, promising to stamp out corruption and end a succession of weak, short-lived governments.

Radev, a Eurosceptic former fighter pilot who has opposed military support for Ukraine, stepped down from the presidency in January to run in the election, which comes after mass demonstrations forced out the previous government in December.

Slick social media campaigns and a promise of stability have boosted Radev’s support in the Balkan country of about 6.5 million people, where voters are weary of repeated elections and a small group of veteran politicians whom many see as corrupt.

“We need, finally, a path to a democratic, modern European Bulgaria,” Radev said after casting his ballot in Sofia. “We need our very robust programme in the parliament to support the Bulgarian citizens to get out as soon as possible of this very difficult situation.”

On relations with Moscow, he said: “I hope that we will develop practical relations with Russia based on mutual respect and equal treatment.”

Rumen Radev speaking to the media after voting in Sofia on Sunday. Photograph: Anadolu/Getty Images

Bulgaria has developed rapidly since the fall of communism in 1989, and joined the EU in 2007. Life expectancy has risen sharply, unemployment is among the lowest in the EU, and the economy is seen as having greater safeguards since joining the eurozone in January.

But Bulgaria lags behind other EU countries in many metrics and there have been concerns about vote-buying in past elections.

The cost of living has become a key issue since Bulgaria, also a member of Nato, adopted the euro. The previous government fell amid protests against a new budget proposing tax rises and higher social security contributions.

That and the recent political crisis appear to be as important to voters as Radev’s calls to improve relations with Moscow or resume Russian oil and gas flows to Europe.

“Politicians need to come together and make decisions – not have constant conflicts and arguments, going from one election to another without getting anything done,” said Bogomil Bardarski, a 72-year-old metalworker who voted in the capital, Sofia.

Opinion polls on Friday suggested Radev’s Progressive Bulgaria party would secure about 35% of the vote. That would mark one of the strongest results by a single party in years, although it would fall short of a parliamentary majority.

Voter interest appears to be up. A poll by the Sofia-based Alpha Research forecasts a turnout of about 60%, nearly double the 34% of June 2024.

The figures highlight the frustration with the dominance of the centre-right GERB party, led by the former prime minister Boyko Borissov, which trails in second place with about 18%, and the centrist Movement for Rights and Freedoms party, whose leader, Delyan Peevski, is under US and UK sanctions related to corruption.

One possible coalition partner is the pro-European We Continue the Change – Democratic Bulgaria (PP-DB) coalition, which also says reform is needed.

Critics say Radev bears some responsibility for controversial decisions taken by interim governments he appointed during his presidency from 2016. These include a 2023 gas deal between the Turkish state gas company Botas and Bulgaria’s Bulgargaz, which led to losses and an investigation.

“The state is basically falling apart,” said Evgeniy Shoh, 50, an IT specialist who voted in Sofia.