The Union of Democratic Forces (SDS) will hear both presidential tickets in the run-off if they ask for its backing, the party's press office said. It will not back anyone who has not asked.
The run-off is on Sunday, 1 November. Iliyana Yotova is running for president with Kiril Valchev as vice-president candidate, and Andrey Gyurov with Georgi Kandev. If either ticket asks for support, SDS will invite it to speak, and the party's National Council will decide.
The party says the campaign was "polluted by attacks, smear material and insulting language". SDS says the first round showed that "Progressive Bulgaria" lost about 1m voters compared with the parliamentary election. It says "We Continue the Change" and "Democratic Bulgaria" got 60,000 more votes than in that election, and that these came from SDS and GERB voters who chose to back Gyurov and Kandev.
SDS recalls that in July it proposed that the democratic camp field one joint right-wing candidate. It says that if the proposal had been accepted, there would be a win today. It blames the arrogance and haughtiness of PP and DB.
The first-round figures are as of 10:00 and come from the website of the Central Election Commission.