Polls are open in Greece for an election that could decide the future of the debt-laden country in the 17-nation eurozone.

The main contenders – the New Democracy conservatives and the Syriza leftist radicals – have pledged to form a government that will renegotiate the harsh austerity conditions of Greece's bailout by the European Union and International Monetary Fund.

Antonis Samaras, New Democracy party leader, has criticized his leftist opponent, Alexis Tsipras, of policies he says will put Greece into a worse situation than it is in now.

Tsipras, leader of the Syriza party, wants to annul the austerity package altogether. Analysts say if the leftists win the Sunday vote, Greece could be forced to leave Europe's common euro currency. If that happens, Greece would reinstate the use of its old drachma currency. Analysts say its value could fall 65 percent in relation to the euro.

After an inconclusive election last month, the top three parties, including the socialist PASOK, were each given a chance to form a coalition, but none of the parties won enough support to put together a new government, prompting Sunday's repeat election.

Greece's Interim Prime Minister Panagiotis Pikrammenos expressed hope that a new government could be formed while casting his ballot Sunday.

“I am certain that my fellow citizens are aware of what is at stake in today's elections, and that elections will bring about a new government as soon as possible, that will deal with the country's serious problems.''

Opinion polls show neither party is expected to win an outright majority in Sunday's election meaning a coalition will have to be formed to avoid another election.

Voting ends at 1600 UTC, with official results expected a few hours later.