He said: ‘Events in Greece could trigger financial fright in Spain, Italy and across the eurozone. The summer of 2012 offers an eerie echo of 2008.

‘If Greece leaves the eurozone, the contagion is impossible to predict, just as Lehman had unexpected consequences.’

Fears are mounting that Spain will be crippled by its banking sector and will be the next domino to fall.

Mr Zoellick said: ‘Eurozone leaders need to be prepared to recapitalise banks. In the eurozone, the guarantees of some national sovereigns are unlikely to be sufficient and only that of the “euro-sovereign” will suffice.