Greek Deputy Prime Minister and Finance Minister Evangelos Venizelos spearheaded a round of blasts by cabinet ministers on Thursday morning over the referendum plan on an EU debt rescue deal.
Upon returning from Cannes, where he had joined Prime Minister George Papandreou in crucial talks on Wednesday night with European leaders, Venizelos cut a clear distance from the prime minister.
"Greece's position within the euro area is a historic conquest of the country that cannot be put in doubt," he said, adding that the achievement by the Greek people should not be decided by a referendum.
Greece should seek instead the prompt implementation of the October 10 agreement at the EU summit to escape a default, he said.
"What is important is for the sixth tranche to be disbursed, without any distractions or delay," said Venizelos, noting that "internal political balances and the future of individuals and political parties of this country is not what matters."
Venizelos' statement increased doubts over the survival of the socialist government under Papandreou ahead of a confidence vote on Friday midnight called by the prime minister, as several "dissidents" within the ruling party warned with a negative vote.
Papandreou's announcement this week that he would hold a referendum on the EU aid package and the country's position in EU triggered a wave of strong reactions within and outside Greece over fears that a negative response by Greek people would destabilize the entire zone of the European common currency.