Just three months ago, the GERB had won the parliamentary election with a good 26 percent.
Revelations about grievances and corruption practices now put a damper on the country.
Sofia - Despite allegations of corruption, Bulgaria's ex-Prime Minister Boiko Borissov's party narrowly won the parliamentary election in the EU country on Sunday, according to forecasts, but clearly missed the absolute majority.
The bourgeois GERB received, according to initial forecasts from three polling institutes, 22.1 to 23.5 percent of the votes in the new election.
The populist and system-critical party “There is such a people” ITN of the entertainer Slawi Trifonow should therefore come with a small gap to GERB at 21.5 to 22.3 percent.
The forecasts are based on voter surveys after voting.
"It may turn out that the vote abroad will be decisive for the election result," said pollster Parvan Simeonov of Gallup International.
Bulgarians are also allowed to vote in 68 countries - from New Zealand to Turkey and EU states such as Germany and Austria to the USA.
According to information from the state radio in Sofia, these results will be announced on Monday.
According to the forecasts, the socialists (ex-KP) would come to 13.5 to 15.1 percent.
The conservative-liberal-green anti-corruption coalition Democratic Bulgaria DB could also make third place.
Six political forces are likely to move into the parliament in Sofia.
The parties of the anti-Borisov camp accuse the former head of government of corrupt administration and exclude a coalition with his GERB party.
As a result of revelations by the current interim government in Sofia about grievances and corruption practices in key ministries, the GERB now fared worse than in the regular parliamentary elections on April 4th.
GERB won the election three months ago with a good 26 percent.
In the European Parliament, the GERB, like the German CDU and CSU, belongs to the European People's Party (EPP).
The official final results should only be available within four days. dpa