Frustrations exploded as Greek President Karolos Papoulias, an 82-year-old veteran of the resistance to Nazi occupation of Greece during World War Two, lashed out at Germany's finance minister for appearing to suggest Greece might go bankrupt.

Past backsliding on promises by Athens has created a growing mood of mistrust, with German Finance Minister Wolfgang Schaeuble likening Greece to a "a bottomless pit" and asking on Wednesday whether Athens would stick to new promises.

"I cannot accept Mr Schaeuble insulting my country," Papoulias riposted.

"Who is Mr Schaeuble to insult Greece? Who are the Dutch? Who are the Finnish?" he asked of critics in two countries which, like Germany, have heaped pressure on Athens.

Greek officials insisted after late-night talks with euro zone counterparts that they had met the final demands set by the European Union and IMF to seal a second rescue deal needed to avoid chaotic default when debt repayments fall due in March.

But the euro slid to a three-week low on the dollar in early Thursday trade as markets focused on a Reuters report that finance officials in the currency union were looking at ways to delay all or part of the rescue deal while avoiding a default.

EU sources told Reuters euro zone officials were studying the option of postponing part or all of the rescue deal until after the elections while still avoiding a disorderly default.

"Confidence has indeed sunk to a low point," Dutch Finance Minister Jan Kees De Jager told Dutch paper Het Financieele Dagblad, suggesting one option was to delay delivering the bailout in full until after a Greek election expected in April.

"Schaeuble Junta," ran a headline in the conservative Eleftheros Typos newspaper, harking back to Greece's painful spell under military rule during the 1960s and 1970s.

Greece is pinning its hopes on a fresh meeting of euro zone finance ministers scheduled for Monday after it failed this week to clinch a deal to avert a bankruptcy which could shake financial markets around the globe.

Finance Minister Evangelos Venizelos said Athens had plugged a 325 million-euro gap in a promised 3.3 billion euros of extra budget savings this year, noting both parties in the government of Prime Minister Lucas Papademos had signed up to austerity measures which already triggered rioting in Athens on Sunday.

Venizelos said he hoped euro zone officials could tie up all the issues before the ministerial Eurogroup meets on Monday, opening the way for a bond swap deal with Greece's private creditors, known as PSI, which will reduce its debt mountain.

"These issues will be prepared at a Euro Working Group meeting on Sunday in Brussels so that, with good faith, the final decision for the approval of the (bailout) program is taken and the public announcement of the PSI is made on Monday," he told reporters after a conference call with euro zone peers.

Greece had said it must initiate a debt swap deal with private bondholders by Friday to meet a March 20 deadline for the 14.5 billion euros in debt repayments. It was hoping to have the euro zone's backing for its second bailout this week. If that backing now comes on Monday, it is possible the debt swap could start in the middle of next week.

LINGERING DOUBTS

After the three-hour conference call among the 17 euro zone ministers, Eurogroup chairman Jean-Claude Juncker said progress had been made but made clear some matters remained open on making sure the bailout plan is carried out in full.

"Further considerations are necessary regarding the specific mechanisms to strengthen the surveillance of program implementation and to ensure that priority is given to debt servicing," he said.

That was echoed by one government official in Germany, where public opinion is hostile to bailing out Greece.

"Questions remain that are very important to Germany and other member states about the sustainability of the program," said the official, who declined to be named.

Juncker predicted things would fall into place by Monday although any number have deadlines have been set, only to be missed.

Greek conservative leader Antonis Samaras - tipped to become prime minister after a possible vote in April - gave a written pledge on Wednesday to stick to the austerity package but added that "policy modifications" might be required to boost growth.

Greece has yet to publicly specify how it will find the remaining 325 million euros worth of budget cuts and the cabinet - which would normally be required to approve such cuts - was not scheduled to meet on Thursday.

A new survey by the VPRC polling company showed Samaras' New Democracy party getting 27.5 percent, down from its 30.5 percent score in January, but still well ahead of the newly-founded Democratic Left party in second with 16 percent.

Italian Prime Minister Mario Monti warned on Wednesday that the debt crisis was fuelling resentment within the bloc and rejected the idea of a "goodies and baddies" division between so-called virtuous northern states and profligate southern ones.

(Additional reporting by George Georgiopoulos and Karolina Tagaris in Athens, and by Brussels, Berlin and Amsterdam bureaus; Writing by Mark John, editing by Mike Peacock)

• A Permanent Economic Emergency