The call for a vote radically raises the stakes in a standoff between Greece and its creditors over the terms for more financial support to the country. Greece's bailout program expires on Tuesday, after which it is unclear whether its banks would be able to avoid collapse.
The Greek Parliament is due to debate and vote at midnight Saturday on the government's request for a referendum as finance ministers from the 19 euro countries, Greece's main creditors, were gathering to discuss the situation in Brussels.
Across Athens, people started flocking to cash machines shortly after Prime Minister Alexis Tsipras announced the referendum, just after 1 am local time.
The length of queues at cash machines, and the availability of cash, varies widely. The Bank of Greece assured, in a statement this afternoon, that the flow of cash to ATMs will not be interrupted.
The Greek government said it would recommend Greeks vote "no" in the referendum. What would happen in that case whether Greece would have to leave the euro or try to renegotiate more time with creditors is unclear.
Former prime minister Costas Karamanlis broke a longstanding silence and severely criticized the government's "foolish choice."
"The nation's most vital interests demand that the country remains at the heart of Europe. The EU's actual shortcomings do not, in any way, negate this..." Karamanlis said. "Foolish choices that undermine this principle push the country to adventures, with unpredictable and possibly irreversible consequences," he added.
