Athens, however, denied there had been any changes to the inspectors' scheduled return early next week, and a spokeswoman for the International Monetary Fund said that staff from the global lender would resume work in Athens on Tuesday.

A team of officials from the IMF, the European Commission and the European Central Bank - known as the Troika - visits Athens regularly to check progress on its bailout commitments and decide whether to release the next tranche of loans.

"There are growing differences between Athens and the Troika," one euro zone official said, adding that the planned trip was, for now, on ice. "The Greeks are saying, 'We are doing enough', and the Troika says they need new steps to close the budget."

Carlos Martin Ruiz de Gordejuela, the European Commission's spokesman in Athens, said, "The Troika will be in a position to resume the review mission in Athens once sufficient information has been received from the Greek authorities to permit us to hold meaningful policy discussions in person." He said if that happened, a return in early November would be feasible.

The latest bailout inspection began in September before being paused and was initially expected to resume in end-October and then slated for resumption on November4.

"They have asked for an appointment on Tuesday. What else can I say?" Greek Finance Minister Yannis Stournaras told reporters in Athens after meeting Prime Minister Antonis Samaras. IMF spokeswoman Angela Gaviria said staff was set to arrive in Athens on Monday and begin work the following day.

Greece has been kept afloat by a financial lifeline from the euro zone and the International Monetary Fund since 2010, with 240 billion euros ($330.5 billion) of loans pledged in exchange for spending cuts and reforms.

After a six-year recession that wiped out 40 percent of household disposable incomes and sent unemployment soaring to almost 28 percent, Greeks are saying they can take no more.

The coalition government argues it deserves some slack after delivering the biggest budget deficit reduction ever recorded in the euro zone. Greece's president said bluntly his country would not yield to pressure from foreign lenders to impose more austerity.

"No one is going because no one wants them (the Troika) there," a second euro zone official said.

MEASURE FOR MEASURE

Stournaras has rejected any new tax increases or across-the-board wage or pension cuts, but said there was scope instead for "targeted" spending cuts and "structural measures" to plug any fiscal gaps.

Since the decision was made in mid-2012 by EU leaders, led by Germany, that Greece must remain part of the euro zone, the assumption has been that any disagreements will be solved.

"The Troika is talking about 2 billion euros. Greece is talking about closing all of that through better control of social security contributions. They say no more measures," a senior euro zone official said.

"The solution is new measures. It will of course happen. It is a matter of miscommunication to their own public."

The first euro zone official said there was still time to sort things out because Greece would only really need the money from the next tranche of loans in February.

According to one source close to the talks, the Troika has yet to be convinced that Athens can deliver on a series of reforms it had promised to implement by the end of September. It needs to complete those "prior actions" to qualify for its next scheduled bailout instalment of over 1 billion euros.

Greece and its lenders are particularly at odds over the future of LARCO, Hellenic Vehicle Industry and Hellenic Defence Systems, three loss-making state companies with 2,100 workers, which cost taxpayers about 150 million euros a year.

The government has yet to prepare its two biggest water companies, EYDAP and Thessaloniki Water, for privatisation by settling all the arrears that municipalities owe them.

It must also convince lenders it will meet a target to put 12,500 civil servants in a "mobility scheme" of forced transfers or dismissals and fire 4,000 others by the end of the year.

The target for Athens is a primary surplus of 1.6 percent of gross domestic product for next year. The government believes it could fall short by just 500 million euros, rather than the 2 billion predicted by the Troika.

The Greek parliament's budget office, whose role is largely advisory and whose opinion is not binding, said in a report on Thursday, "It remains open whether Greece next year will achieve a 'primary budget surplus', such as the one agreed in the medium-term bailout plan."

Greek authorities say a growing economy is the only way to reduce the country's debt, which stands at about 320 billion euros or 175 percent of its GDP. The Troika holds almost 80 percent of that debt.

(Additional reporting by Harry Papachristou in Athens and Tim Ahmann in Washington; Editing by Andrew Roche and Peter Cooney)

By Martin Santa and Jan Strupczewski