Greece's deputy prime minister said the government would emerge stronger after winning a confidence vote later on Wednesday and be able to secure parliament's endorsement for an accord to end a dispute over Macedonia's name.
Prime Minister Alexis Tsipras called the confidence vote following the resignation of his right-wing coalition partner Panos Kammenos in protest over the accord.
Greek opponents of the agreement say Macedonia's new name - the Republic of North Macedonia - reached after decades of dispute between Athens and Skopje - represents an attempt to appropriate Greek identity. Macedonia is the name of Greece's biggest northern region.
Tsipras has said that if he wins the vote with an absolute majority of 151 in the 300-seat parliament, he will bring the so-called Prespes agreement to parliament for approval this month. If he fails, he said he would call a snap election.
An early election could delay reform implementation, privatisations and Greece's efforts to return to bond markets. Tsipras' party is trailing by up to 12 points behind the main conservative New Democracy party, which opposes the deal.
"The government will win a confidence vote and rise stronger and more coherent from this process," Deputy Prime Minister Yannis Dragassakis told lawmakers hours before the vote takes place, around midnight (2200 GMT).
"The Prespes agreement will be endorsed because there is the (required) parliamentary majority."
Dragassakis said that winning both votes would restore political stability in the country that just emerged from its third international bailout since 2010 and allow Greece to return to bond markets when the time is right.
Based on the country's constitution, Tsipras only needs to secure half of those present during the vote and at least 120 votes out of the house's 300 to win. But he wants to get 151 votes and have an absolute parliamentary majority.
Tsipras' Syriza party has 145 seats in the 300-seat chamber and the support of one independent lawmaker, and needs at least five more to get past the threshold of 150 deputies.
Four dissenters from Kammenos's party said they would support the prime minister, while one lawmaker from the small centrist To Potami party said he would also back Tsipras.
Government spokesman Dimitris Tzanakopoulos told Greek TV on Wednesday that the government wants the Macedonia name agreement also approved with 151 votes.
Macedonia's parliament last week passed an amendment to the constitution to rename the country, leaving it up to Greece to ratify the deal. Greek parliamentary endorsement is needed for the tiny Balkan nation to join the European Union and NATO.