The Bulgarian Socialist Party (BSP) is to meet with two other left-wing organizations on Tuesday, in an attempt to mend fences and seek a joint nomination for this autumn's presidential elections.

The meeting follows an internal referendum which the BSP held earlier to ask its members whether they wish to join forces with ABV party of former President Georgi Parvanov, which splintered off the BSP in 2014. A narrow majority if 52% backed the move. Some 49% voted for talks with a smaller left-wing party, Movement 21 (with the two groups largely overlapping). A total of 72% of those who cast a ballot were in favor of coalition talks.

The BSP is Bulgaria's second-largest party and the biggest one in opposition. Its leader Korneliya Ninova had promised to call the referendum after her election in the spring.

Ninova inflamed tensions after the poll by ruling out that either Parvanov or Ivaylo Kalfin, one of the parties' deputy head, could become joint candidates, drawing anger from ABV itself.

However, the socialist leader also ruled out the possibility of running.

She will hold a meeting with ABV in Parliament at 14:30 local time. Another round of talks is scheduled with Movement 21 of Tatyana Doncheva, who quit the BSP in 2013.

No major party in Bulgaria has announced a presidential candidate, with the vote due either late in October or early in November.

ABV's Parvanov, who served two times as President and vacated the office in 2012, has hinted he is ready to run again if there are no constitutional barriers.