Polls have opened in Greece to vote in a referendum on whether to accept tough conditions sought by international creditors to extend a lending lifeline keeping the country afloat.
Dozens of people were queuing outside schools and university buildings transformed into polling stations as doors opened at 7:00am local time.
"I'm voting 'No' because I think it's better for the country," said 80-year-old Michelis, first in through the doors of a school being used for the vote on Skoufa street in central Athens.
"If we vote 'No' they'll take us more seriously," he said, adding that he was "not voting for myself, but for my grandchildren" and their future.
Theodora, 61, a retired journalist, said she was voting "Yes" because "it's a 'Yes' to the European Union".
The country's total debt load stands at a staggering 323 billion euros ($477 billion), three-quarters of it owed to its troika of creditors.
Earlier this week, Greece became the first developed economy to fall in arrears to the International Monetary Fund (IMF) when it missed a 1.5-billion-euro loan repayment.
Photo: A man withdraws money from an ATM in downtown Athens on the eve of the key referendum. (AFP: Andreas Solaro)
The outcome of the referendum could determine Greece's future as a member of the single currency.
Polls close at 7:00pm local time (2:00am Monday AEST) with projected results expected to be announced by 9:00pm.
Greek finance minister Yanis Varoufakis said he was optimistic about a deal with international creditors regardless of the outcome of the referendum. However, he said he would resign if people vote "Yes".
But he said there was too much at stake for Europe to cast Greece adrift.
"As much for Greece as for Europe, I'm sure," Mr Varoufakis told the Spanish newspaper El Mundo.
"If Greece crashes, a trillion euros [the equivalent of Spain's GDP] will be lost. It's too much money and I don't believe Europe could allow it.
"What they're doing with Greece has a name: terrorism.
"Why have they forced us to close the banks? To frighten people. And when it's about spreading terror, that is known as terrorism."
As tensions rose, he was also forced to deny a Financial Times report that suggested Greek savers could lose 30 per cent of their bank deposits to shore up the banking system, describing it as a "malicious rumour".
A slew of opinion polls on Friday gave the "Yes" camp, which favours accepting the bailout terms, a slender lead but all were within the margin of error and pollsters said the vote was too close to call.
Only one had the "No" vote advocated by the government ahead.
Addressing a crowd of over 50,000 in central Athens, left-wing prime minister Alexis Tsipras urged them to spurn the deal, rejecting warnings from Greece's European partners that this may bring an exit from the euro and even greater hardship.
Years of Greek debt
The Greek debt crisis has rumbled on for six years and could culminate in the country's exit from the Eurozone.
- 2001: Greece joins the Eurozone
- 2009: Papandreou government reveals the national public deficit was nearly three times more than accounted for, at 15 per cent of GDP
- 2010: Athens appeals for aid from the EU and IMF; becomes first Eurozone country to receive a bailout amounting to 110 billion euro in exchange for painful austerity measures
- 2011: Private sector creditors agree to write off half the debt owed to them
- 2012: Second bailout of 130 billion euro
- 2015: In five years, national output is cut by 25 per cent, salaries fall by more than that, quarter of workforce is unemployed
- January 25: Anti-austerity Syriza party, led by Alexis Tsipras, wins snap election with a pledge to renegotiate the bailout terms
- February 20: Greek authorities and its creditor institutions agree to extend aid until the end of June
- June 5: Mr Tsipras rejects creditor demands for pension cuts and labour market reforms
- June 17: Greek central bank warns for the first time of Grexit if it fails to reach a bailout deal
- June 27: Mr Tsipras calls for a surprise July 5 referendum on bailout proposals; Eurozone finance ministers refuse to extend bailout past June 30; bank customers rush to withdraw cash
- June 28: Government orders banks to close until July 7 and imposes capital controls as ATMs run dry
- June 30: Greece's bailout officially expires and the country defaults on a 1.5 billion euro debt payment to the IMF
- July 5: Greeks vote in a knife-edge referendum
From other news sites:
- BBC: Greece debt crisis: Mass rival rallies over bailout vote
- The Sydney Morning Herald: Eurozone crisis: Confusion reigns in Greece on last day before referendum
- The Guardian: Yanis Varoufakis accuses creditors of terrorism ahead of Greek referendum
- Daily Telegraph: Greece crisis live: 'no' vote in referendum would trigger economic meltdown
- Reuters: Greece votes in referendum with future in euro in doubt