The senior Greek politician said Athens would call for an emergency EU leaders' summit if the Eurogroup failed to convene on Friday to discuss its application for a loan extension.

The new government wants separately to negotiate the conditions attached to the loan at a later date, which has been called unacceptable by German finance minister Wolfgang Schaeuble.

Greek negotiators say it is a "tactical manoeuvre" designed to give both sides more time to develop a new rescue package, which would would be less onerous on the Greek people.

Criticising Germany's approach to the talks, a Greek government source told Sky News: "Germany has been overtaken by arrogance."

He continues, "It's like being back in the 1940s, being asked to surrender."

The €240bn bailout, which came with more than 400 conditions - including reducing the public sector, shrinking pensions and lowering the minimum wage - expires in 10 days.

There are fears that if a deal is not agreed in outline this week, then Greece could start to have difficulty servicing its debts.

That could lead to more capital being pulled out of Greek banks and a so-called messy default, which could see a return to the drachma.

A source told the Associated Press news agency that Greece will ask for an extension of up to six months of a loan agreement with the euro zone, on conditions to be negotiated.

AP says the source drew a distinction between a loan agreement and the full bailout programme, which the Greek government insists is dead.

Mr Schaeuble dismissed the suggestion of an extension, telling broadcaster ZDF: "It's not about extending a credit programme but about whether this bailout programme will be fulfilled, yes or no."