The Greek public has been in an uproar for months over the government's repeated rounds of austerity measures, holding near-daily strikes, sit-ins and protests that sometimes degenerate into riots. - AP photo

ATHENS: Demanding that the prime minister resign, the main Greek opposition leader led his party in a dramatic walkout Thursday during a parliamentary debate about the viability of the government.

Antonis Samaras' statements came amid an intense political crisis in Greece, after Prime Minister George Papandreou shocked the country, European leaders and financial markets earlier this week by saying he wanted to put a hard-fought new European debt deal to a popular vote.

World markets tanked as investors fretted over the prospect of Greece being forced into a disorderly default or out of the 17-nation eurozone.

Papandreou abandoned that plan Thursday as the uproar spread even to his own ruling Socialist party.

Greece's new debt deal would give the country an extra (euro) 100 billion ($138 billion) in rescue loans from the rest of the eurozone and the International Monetary Fund _ on top of the (euro) 110 billion ($152 billion) it was granted a year ago. It would also see banks forgive Athens 50 percent of the money it still owes them. The goal is to reduce Greece's massive debts to the point where the country is able to handle its finances without constant bailouts.

Samaras, the opposition leader, did not indicate whether he would vote in favor of the deal when it comes before parliament. But he claimed that he had said from the start that the latest European agreement was ''unavoidable.''

Earlier, Samaras had called for a transitional government to take over in order to safeguard the new deal agreed on barely a week ago after a marathon European summit in Brussels, and to ensure Greece gets a vital (euro) 8 billion ($11 billion) installment of its existing bailout agreement.

Papandreou ignored widespread calls for his resignation but withdrew the referendum plan, with his finance minister, Evangelos Venizelos, saying there was no longer need for one as the opposition indicated it backed the debt deal.

But a furious Samaras said Papandreou had misunderstood.

''Mr. Papandreou pretends that he didn't understand what I told him. I called on him to resign. He set fires everywhere, and returned as if nothing happened,'' he thundered in Parliament. ''A return to normality means elections _ within the next six weeks if possible.''

Samaras said Papandreou ''nearly destroyed Europe and the euro ... and all this to claim that he wanted to blackmail us into accepting the loan arrangement, even though I had said it from the beginning that it was unavoidable.''

The Greek public has been in an uproar for months over the government's repeated rounds of austerity measures, holding near-daily strikes, sit-ins and protests that sometimes degenerate into riots.