Voters will go to the polls in Bulgaria for the second time in three months this weekend after no party secured enough support in an April parliamentary election to form a government.
Former three-time Prime Minister Boyko Borissov's GERB party performed best in the inconclusive election, but it received only 26% of the vote. Public discontent over widespread reduced the party's popularity from four years earlier, when it had 33% of the vote.
The latest opinion polls indicate that support for GERB has dropped further since an interim government Bulgaria's president installed in May opened investigations into alleged corruption during Borissov's time as prime minister.
Polls suggest a neck-to-neck race between Borissov's party and its main rival, the anti-elite There is Such a People, which is led by popular TV entertainer Slavi Trifonov.
"There are two clear trends in the last couple of months: erosion in support for the GERB party, mainly due to the actions of the caretaker government, and a slight but clear growth of There is Such a People," Dimitar Ganev, a political analyst with Bulgarian research firm Trend, told The Associated Press.
He sees no chance for political maverick Borissov, 62, to return to office for a fourth term regardless of whether GERB finishes first in Sunday's election.
"I expect the next government to be formed by the so-called protest parties," Ganev said.
Borissov previously managed to draw backing at home and abroad by combining populist man-in-the street rhetoric with pro-Western slogans.
But thousands took to the streets during month-long protests last year and accused Borissov and his government of protecting oligarchs, refusing to reform the judiciary and suppressing freedom of speech.
The interim government's investigations have shed additional light on some of those accusations.
Caretaker ministers have alleged that dozens of opposition politicians were illegally wiretapped before the April election. They also have claimed that billions in public money was distributed to favored private companies without a bidding process and that businesspeople have become objects of intimidation and extortion.
Bulgaria, a member of both the EU and NATO, also has come under scrutiny from its Western partners due to its long-standing problems with corruption, adhering to the rule of law and preserving freedom of the media.
The U.S. government last month sanctioned several Bulgarian public officials and businessmen, including two powerful oligarchs, and their networks encompassing dozens of companies over their allegedly "extensive" roles in corruption. The U.S. Treasury said the move was its single biggest action targeting corruption to date anywhere in the world under the Magnitsky Act.
Political analysts assume the U.S. sanctions, imposed just weeks before the election, could additionally boost the anti-corruption arguments of the protest parties.
A key question in the upcoming vote is whether There Is Such a People and two other parties will win enough seats in parliament to form a viable coalition government.