Bulgarians vote in their fifth parliamentary election in two years on Sunday amid rising resentment towards political elites who many see as unwilling to tackle graft and economic reforms.
Opinion polls show the ballot will likely leave Bulgaria short of a functioning parliamentary majority again, putting in question its ambitions to join the euro zone in the near term and effectively use European Union COVID recovery aid.
In the running is a coalition of the center-right GERB party of former long-serving premier Boyko Borissov, 63, and its small Union of Democratic Forces (SDS) partner, as well as the newly established coalition of the pro-Western We Continue the Change (PP) party and reformist Democratic Bulgaria (DB).
"Regardless of which of the two comes first, it does not solve the big question - what are the prospects of forming a government," said Genoveva Petrova of Alpha Research.
"Parties in Bulgaria have had four interim parliaments to realize that there is no political force at the moment that has not just an absolute majority but a large enough advantage to set the agenda," Petrova added.
Voting ends at 8 p.m. (1700 GMT).
The two coalitions are neck and neck in opinion polls, with the latest by Exacta Research Group showing them at 26.2% and 25.6%, respectively, and the nationalist Revival party at 12.8%.
Complicating coalition building are accusations by many of his political rivals that Borissov had not done enough to stop corruption in the country during his decade-long rule that ended in 2021, something that Borissov denies.
"It is not normal to not have any political dialogue, there is no will ... to consolidate so that things get better," said Ivailo Atanasov, 47, in Sofia.
At stake could also be Bulgaria's stance on Russia's war in Ukraine. Once an ally of President Vladimir Putin, Sofia has supported Kyiv since Moscow launched what it calls its special military operation in Ukraine.
The two coalitions in the running on Sunday want Bulgaria to maintain its pro-Ukraine stance but President Rumen Radev, who has wielded much power throughout the political instability, has pushed for a more nuanced approach.
