International spotlight on Greek elections

Parties espousing either side of the argument were almost neck-and-neck when official polls stopped at the beginning of June.

The leading centre-right New Democracy party, headed by Antonis Samaras, says it will seek concessions on the tough conditions attached to the latest €130m bailout - with Greek society already teetering under the social welfare and wage cuts and rising unemployment - but will essentially stick with the programme demanded by Greece's creditors.

But it is radical left party Syriza that has attracted much of the attention both inside and outside Greece. Its leader Alexis Tsipras has promised to scrap the programme entirely. He says he will replace it with a national plan to achieve a balanced budget that would focus on raising taxes, rather than cuts.

Greece's euro partners regard Tsipras with alarm. They say Athens must honour its previous commitments otherwise the money will stop flowing. This would push Greece into default and probable exit of the single currency.

Greeks went to the polls just six weeks ago. But the results proved inconclusive when no governing coalition could be formed. It was the date that the rest of the Europe work up to the Syriza party, which, speaking to austerity-weary Greeks, scooped second place with 16.8 percent of the vote.

Since then EU leaders have been obliquely warning Greeks about the potential consequences of their vote on Sunday. They say they want Greece to remain in the euro, but that it cannot be at any price.

Tsipras, for his part, has been calling his euro partners' bluff. He has regularly told supporters that the eurozone will not let Greece go because the political, social and economic consequences would be too high.

The uncertainty has been making markets more jumpy than ever and has contributed to driving up borrowing costs in Spain and Italy. Meanwhile banks in Greece are reporting a steady withdrawal of millions of euros in savings every day.

Although politicians outside Greece are avoiding overt statements on Sunday's election, plans are being made for the worst case scenario. Member states have been discussing the extent to which they can impose capital controls and border checks should Greece leave the eurozone.

Central banks around the world have been preparing for shock market reaction to the election outcome by ensuring liquidity.

The polls open at 6am Brussels time and close 12 hours later. The first exit polls are expected to be released soon after voting finishes.