ATHENS (Reuters) - Greek Prime Minister Alexis Tsipras on Sunday said he would call a confidence vote in his government after his coalition ally quit, leaving him bereft of a parliamentary majority and raising the possibility of snap elections.

Earlier, Greece’s right-wing defense minister resigned in protest at a deal ending a long running dispute with Macedonia over its name, saying he was taking his other six ministers in cabinet with him.

The crisis left the fate of a 2018 deal changing the name of Macedonia to North Macedonia in limbo. Greek parliamentary endorsement of the name is required for the tiny Balkan nation to join the European Union and NATO. Macedonia’s parliament has already ratified the accord with a constitutional amendment.

Outgoing Defense Minister Panos Kammenos’s Independent Greeks party had seven MPs, enough to get Tsipras’s administration past the threshold of 150 deputies in the 300-member parliament. Tsipras’s Syriza party has 145 seats and also the support of one independent lawmaker.

“I have taken my decision and have informed the president of parliament that we will immediately move to the process outlined by the constitution for the renewal of the confidence in my government,” Tsipras told journalists.

The confidence vote is expected to take place later this week and parliamentary speaker Nikos Voutsis proposed Jan. 16. Kammenos said he would not support Tsipras in the vote.

Syriza is trailing between eight and 12 points behind the main conservative New Democracy party, which also opposed the deal with Macedonia, in pre-election polls.

A firebrand leftist, Tsipras was elected in 2015 on a platform of anti-austerity but was forced into a third international bailout to bring back Greece from the brink of bankruptcy. The country exited a bailout program in mid-2018.

Kammenos, who forged a coalition pact with Tsipras in 2015, never concealed his hostility to the deal with Skopje.

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Greece has a province called Macedonia and long demanded Skopje change its country name to remove what Athens considered to be an implied claim to Greek sovereign territory.

The wrangle had long frustrated Macedonia’s EU and NATO aspirations. Greece is a member of both institutions and has a say in who gets to join, like other member countries.

Kammenos said that any deal including “Macedonia” in the name of the Balkan state to Greece’s north was unacceptable as the name was irrevocably tied to Greek civilization and culture.

The Greek parliament’s vote on the name deal has been expected later this month. The government hopes the pact will pass with the support of center-left and independent lawmakers.