Greeks are withdrawing their cash out of banks and stocking up with food ahead of Sunday's election that many fear will result in the country being forced out of the euro.
Bankers said hundreds of millions in euros were leaving major banks daily in the run up to the country's second parliamentary poll in as many months.
Retailers said some of the money was being used to buy pasta and canned goods, as fears of returning to the drachma, the country's former currency, were fanned by rumours that a radical leftist leader may win the election.
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The last published opinion polls showed the conservative New Democracy party, which backs a $160bn bailout to keep Greece afloat, running neck and neck with the leftist Syriza party, which wants to cancel the rescue deal.
As the election approaches, publishing polls is now legally banned, but party officials have been leaking contradictory "secret polls".
On Tuesday, some of those polls were said to point to Syriza leading by a wide margin, but this was denied by at least one reputable poster.
"This is nonsense," a member of the company said on condition of anonymity.
"Our polls show the picture has not changed much since the last polls were published. Parties may be leaking these numbers on purpose to boost their standing."
'People are terrified'
Both New Democracy and Syriza say they want Greece to remain in the single currency but the leftist party has pledged to scrap the bailout agreement signed in March which has imposed some of the toughest austerity measures seen in Europe in decades.
The European Union and International Monetary Fund, who are financing the bailout,have warned that Greece, which has only enough cash to last for a few weeks before defaulting, must stick to the conditions of the deal or risk seeing funds cut off.
New Democracy has been telling voters they must choose between the euro or the drachma, while Syriza promises to end the austerity measures imposed by Greece's international lenders, such as salary and pension cuts, that have driven many Greeks into abject poverty.
Fears that Greece will collapse financially and leave the euro have slowly drained Greek banks over the last two years.
Bankers said the pace was picking up ahead of the vote, with combined daily deposit outflows from the major banks at 500 to 800 million euros over the past few days.
Retailers said consumers were stocking up on non-perishable food, while almost all other goods were seeing a huge drop in sales as cash-strapped Greeks have no money to spare in the country's fifth year of recession.
"People are terrified by the prospect of returning to the drachma and some believe it's good to fill their cupboard with food products," said Vassilis Korkidis, head of the ESEE retail federation.
"It's over the top, we must not panic. Filling the cupboard with food doesn't mean we will escape the crisis."