Wall Street markets are suffering huge falls this morning as fears grow that Europe's plan to save the euro will unravel before it can even kick in.
Greek Premier George Papandreou said he will put Greece's bailout through a referendum, throwing the long-awaited deal into disarray.
Financial markets around the world have tumbled in reaction to the shock announcement today and U.S. stocks have also fallen at the open.
Wall Street: Financial markets around the world have tumbled in reaction to the shock announcement and U.S. stock futures are down on Tuesday
The Dow Jones opened down 258 points, or 2.2 per cent; the Nasdaq fell 78 points, or 2.9 per cent, and the S&P fell 33 points, or 2.7 per cent.
‘The market did not see this Greek referendum coming, which is potentially a killer,’ said Vermont investment strategist Paul Mendelsohn.
‘It could knock the wheels off the bus of the whole (Europe rescue) plan.’