The Greek government will again distribute one-off Christmas payments to low-earners, drawing from a budgetary surplus built on severe spending cuts and high taxes, the country's prime minister said.

Bailout negotiators have returned to Greece to try and reach a deal by the end of the year on the terms for the next loan payout, as the debt-plagued country prepares to end eight years of rescue funding programmes next summer.

A planned meeting of European Union leaders has been cancelled as crisis talks continue about Greece's place in the single currency zone.

Protesters have clashed with riot police in Greece in the first display of anti-government sentiment since the leftist Syriza party took power a month ago.

Greeks have begun voting in their second election in six weeks, and arguably their country’s most critical vote in 40 years, with its treasured place within the European Union’s joint currency in the balance.