Greek Prime Minister Alexis Tsipras announced on Sunday that he will call a confidence vote in the government after his coalition partner quit over a long-standing name dispute with neighbouring country FYR Macedonia.
Panos Kammenos, whose Independent Greeks party props up Tsipras minority government, announced his resignation on Sunday morning after a meeting with Tspiras.
"The Macedonia name issue...doesn't allow me not to sacrifice the minister's chair," Kammenos said. He added that the party's other ministers will also walk out.
Tspiras told reporters after the meeting that he has "informed the president of the parliament that we will immediately move to the process outlined by the constitution for the renewal of the confidence in my government.
The vote is expected to be held later this week. Kammenos has already stated that the Independent Greeks would not support the ruling Syriza party.
Greece has a parliamentary election scheduled for October and Syriza is currently trailing the centre-right New Democracy party, which also opposes the deal with FYR Macedonia, by 12 points.