Greek Prime Minister George Papandreou on Sunday called for a vote of confidence into his government and said a referendum on changes to the political system would take place in the autumn, DPA reported.
The country was "at a crossroads," he told parliament. "I ask parliament to renew its confidence in the government." The vote is to take place late Tuesday. The governing Socialists have 155 seats in the 300-seat parliament.
Antonis Samaras, the head of the largest opposition party, Nea Dimokratia (ND), said Papandreou's drastic savings measures had not achieved any results. "We will not give you our trust," he said.
The Greek debt problem had not yet ended, Papandreou said, and the country and its EU partners had to concentrate on avoiding bankruptcy, or "sudden death." This could only be achieved with the support of all the country's political and social forces, he said.
He said that citizens would be given the chance to decide on "the modernization of the state" in the autumn referendum, without giving further details.
Papandreou reshuffled his cabinet on Friday in an effort to push through the latest reforms, which include cutting public salaries and increasing taxes to make savings of 28 billion euros (40 billion dollars). Privatization is expected to generate an additional 50 billion euros.
The programme is a pre-condition set by the International Monetary Fund (IMF) and the European Union, who are due to approve the next tranche of a bailout fund for the country worth 12 billion dollars this week.
Greece has also asked for a second bailout - thought to be worth about 80 to 120 billion euros - needed to keep Greece solvent beyond 2012, when coverage from the current rescue package starts to tail off.
Meanwhile, a survey published survey by the weekly To Vima newspaper said that 47.5 of Greeks were against the measures, though 79.8 per cent of people still supported membership of the European Union.
Over 70 per cent of Greeks said they wanted a cross-party government to take the country through the time of crisis.