Borisov had said before the election that if Tsacheva failed to come first in the first round, he would call early elections
Bulgarian Prime Minister Bokyo Borisov suffered an embarrassing setback in the first round of presidential elections Sunday, with exit polls suggesting his candidate fell short of the top spot.
Tsetska Tsacheva won 22.5-23.5 percent of the vote, behind first-placed Rumen Radev. on 24.8-26.7 percent, the candidate of the opposition Socialists seen as more sympathetic to Russia.
The result, if confirmed, sets up a tight runoff contest on November 13 between Tsacheva, 58, who is speaker of parliament, and former air force commander and ace MiG pilot Radev, 53.
Borisov, 57, had said before the election that if Tsacheva failed to come first in the first round, he would call early elections.
This could plunge the EU's poorest and arguably most corrupt country -- the average monthly salary is just 480 euros ($535) -- into renewed political turmoil.