The Greek government has told rebellious lawmakers that failure to back a deeply unpopular European rescue package in parliament will send the nation down an unknown, dangerous path to default and international economic isolation.
Officials are hammering home the message that the country's future in the euro is at stake.
The package of austerity measures demanded by the European Union and the International Monetary Fund in return for a €130 billion bailout was approved by the Greek cabinet on Friday.
The coalition of Prime Minister Lucas Papademos has a huge majority, which should ensure parliament approves on Sunday a package including a further €3.3 billion euros in budget cuts this year, needed to secure Greece's second bailout since 2010, Reuters reports.
But the number of dissenters is growing. About 20 MPs belonging to the two major parties backing Mr Papademos shrugged off their leaders' threats and warned they might reject the bailout.
However, it would take more than 80 rebels to scupper the law in a vote scheduled for late on Sunday.
Six members of the Papademos cabinet have already resigned over the heavy pay, pension and job cuts which the European Union and International Monetary Fund are demanding as the price of the funds, which Greece needs by March to avoid a messy bankruptcy.
Deputy Finance Minister Filippos Sachinidis says the consequences of a disorderly debt default would be incalculable.
As a 48-hour protest strike went into its second day, about 50 Communist party activists draped two huge banners on the ramparts of the Acropolis on Saturday, reading: "Down with the dictatorship of the monopolies (and the) European Union".
About 7000 demonstrators gathered in central Athens, police said, but there was no repeat of trouble on Friday when police fired teargas at protesters throwing petrol bombs and stones.
Those earning the minimum wage are furious that their salaries will now be cut from €751 a month to €600.
Civil servants worry they will be in the firing line as 15,000 jobs are cut this year.