Opinion polls suggest the election will be a closely contested affair between Syriza and the two mainstream parties — New Democracy and Socialist PASOK — that alternated in power for the past four decades and which have lost more than half their support.
JP Morgan Chase Bank analyst David Mackie raised the likelihood of a Greek euro exit from 20 percent to 50 percent if Syriza wins the elections and rejects the austerity measures outright.
Mackie said a Greek eurozone exit would see the country's gross domestic product shrink by as much as 25-30 percent.
In the streets of Athens, people expressed a mixture of apprehension over the future of the country and anger with politicians who let it come so far.
"For me, the political system needs to sit down and come to an understanding because they are killing our country, that is for sure," said Athens resident Georgia, who didn't give her last name. "If they don't do it, our country will be lost."
Juergen Baetz in Berlin and Menelaos Hadjicostis in Athens contributed
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