Investment bank Morgan Stanley has warned the ramifications of Greece exiting the euro are more serious than markets are anticipating, with a full-scale eurozone collapse now more likely.
Furious Greek citizens have attacked Christine Lagarde, head of the International Monetary Fund (IMF), after she accused some of "trying to escape tax."
Citigroup's top economist Michael Saunders has forecast Greece will exit Europe's single currency on 1 January 2013, and its new currency will immediately depreciate by 60%.
German Chancellor Angela Merkel and other senior European Union (EU) officials last night called on Greece to shelve plans to quit the single currency and urged it to see out its austerity programme.
European equity markets have given up all yesterday's gains as investors remain on the back foot ahead of today's EU summit.
Chancellor George Osborne has said the UK government is making contingency plans for a Greek exit from the euro as the crisis in the region reaches a "critical" point.