Democratic Left (DIMAR) is due to hold its party conference next Thursday, with leader Fotis Kouvelis coming under increasing pressure.
The former coalition partner has seen its fortunes tumble over the last few months, which included receiving just 1.2 percent of the vote in the European Parliament elections in May. Kouvelis is expected to face criticism at the conference.
MP Yiannis Panousis has already made it clear that he will only attend the event in order to publicly decry Kouvelis for failing to have a clear strategy.
At least five other DIMAR MPs have expressed their unwillingness to back the government’s candidate for president, with Kouvelis yet to make his position clear. He has denied suggestions that he might be in line to succeed current President Karolos Papoulias.