Failure to strike a deal to secure the 130-billion-euro ($170 billion) rescue risks pushing Athens into a chaotic debt default which could threaten its future in the euro zone.

European Union (EU) officials say the full package must be agreed with Greece and approved by the euro zone, European Central Bank and International Monetary Fund before February 15 to allow time for complex legal procedures involved in the bond swap to be completed in time for a March 20 bond redemption. ?

In some euro zone countries, including Germany and Finland, parliamentary approval is required to raise the bailout money.

In Paris, German Chancellor Angel Merkel on Monday expressed the exasperation among euro zone leaders at seemingly endless arguing in Athens that has yet to produce a definitive acceptance of the austerity and reform demanded by the lenders.

"I honestly can't understand how additional days will help. Time is of the essence. A lot is at stake for the entire euro zone," she told a news conference with French President Nicolas Sarkozy.

But leaders of the three parties in the coalition government appeared to need at least one additional day.

The office of Prime Minister Lucas Papademos, a former central banker who heads a government of politicians, said that a meeting of leaders from the conservative, socialist and far-right parties due on Monday had been postponed to Tuesday.

No reason was given for the delay. Papademos held further talks with the "troika" of lenders - the European Commission, ECB and IMF - on Monday.

The party leaders, positioning themselves for a likely general election in April, have balked at accepting another package of deeply unpopular wage and pension reductions, job cuts and tougher tax enforcement measures.

Alarmed by the prospect of yet more budget cuts, Greece's two main trade unions said they will hold a 24-hour strike on Tuesday in protest against policies they say have only driven the economy into a downward spiral. ?

Demonstrations are planned in central Athens. ?