Greece's government looked on the verge of implosion on Tuesday ahead of a Friday confidence vote as a socialist deputy defected and another cadre called for early elections after the prime minister called a referendum on his EU debt rescue.

Greek Prime Minister George Papandreou called the referendum late Monday in a bid to secure approval of his disputed economic policies without early elections.

But the gambit backfired when a former deputy minister defected, reducing the ruling party's majority in the 300-seat parliament to 152 deputies.

Moments later, the head of parliament's economic affairs committee Vasso Papandreou called for an early ballot and a temporary unity government to "safeguard" the EU deal agreed last week to slash Greece's huge debt by nearly a third.

"I call on the president to convene the council of political leaders with the goal of forming a government of national salvation in view of safeguarding the EU package agreed on October 27, and then to immediately hold elections," said Papandreou, who is not related to the prime minister.

Source: Agence France-Presse