ATHENS (Reuters) – Greece’s Alexis Tsipras appeared set to win a confidence vote after winning the support of an opposition centrist lawmaker who broke ranks with his party on Tuesday, giving the prime minister the final vote he needs to survive.

Tsipras called the confidence vote following the resignation of Defence Minister Panos Kammenos and his Independent Greeks’ party over an accord to end a long dispute between Greece and Macedonia by changing Macedonia’s name.

Parliament will begin a debate on Tuesday and the vote is expected on Wednesday night.

The prime minister said last week he could call a snap election if he failed to win a majority of 151 votes.

His leftist Syriza party has 145 seats in the 300-seat chamber and the support of one independent lawmaker. Despite the resignation of Kammenos, four lawmakers from the right-wing Independent Greeks have said that they will still back him, leaving him a single seat short of a majority.

Tsipras secured what appeared to be the pivotal vote on Tuesday when an official from the small To Potami party said its member Spyros Danellis had announced his backing.

“Danellis called (Potami leader) Stavros Theodorakis late last night and told him that he will support the government,” the party official told Reuters.

The fate of the Macedonia name deal hinges on the outcome of the confidence vote, as the opposition has vowed to reject it.

The deal, reached last year, is intended to resolve a dispute that has kept Greece’s northern neighbour excluded from the EU and NATO over its name.

Greece argues that the name Macedonia represents a territorial claim over a Greek province by the same name, and has blocked the former Yugoslav republic from joining Western institutions. Under the deal, Macedonia will change its name to the Republic of North Macedonia, and Greece will accept it.

To Potami had been expected to support ratification of the accord, but Danellis’s defection prompted a rethink.

“We have second thoughts,” said Potami’s George Mavrotas when asked by state TV if his party’s stance on the deal had changed. “We’ll weigh emotions and logic and make our final decisions.”

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 opponents of the agreement say Macedonia’s new name still represents an attempt to appropriate Greek identity. Groups opposing the deal will rally in central Athens on Sunday.

Kammenos, who has called the deal a national sell-out, handed the defence ministry to his successor, Evangelos Apostolakis, who had held the position of armed forces chief.