He said: 'Patience is running out in the international community. There is a sense from across the leading lights of the eurozone that time is running out for them.

'The eurozone has six weeks to resolve this political crisis.'

Mr Osborne also signalled dramatic plans to prop up Britain's faltering economy, opening the door for a  rescue plan that would see the  Bank of England lend directly to struggling small businesses.

In other developments:

There is a growing expectation in Whitehall that the Bank of England will authorise another emergency injection of cash into the economy with a second round of 'quantitative easing' – essentially, printing money.

As much as £300billion is expected to be flooded into the economy despite the risk that it will push inflation still higher, increasing the cost of living.

The Bank has already poured £200billion into the economy to try to bolster growth, but there have been renewed calls for another dose of the medicine.

Mr Osborne, in Washington, signalled that he is open to the idea of the Bank ring-fencing some of the cash for direct loans to small or medium-sized firms that are in urgent need of help to expand or simply keep afloat.