Greeks began voting on Sunday in the first round of local elections that mark Prime Minister Antonis Samaras’s first big electoral test since coming to power two years ago.

Greeks began voting on Sunday in the first round of local elections that mark Prime Minister Antonis Samaras's first big electoral test since coming to power two years ago.

The vote, along with European Parliament elections a week later, are being closely watched as a gauge of sentiment towards Samaras's fragile coalition, which could be in jeopardy if the far-left Syriza and far-right Golden Dawn parties fare well.

Nearly 10 million Greeks are eligible to vote on Sunday to elect mayors and town councils for 325 municipalities as well as prefects - similar to state governors - for 13 regions across Greece, with a run-off vote to be held on May 25.

After six years of recession and repeated waves of austerity measures that have shrunk incomes and pushed unemployment over 26 percent, the election is being fought as much on national issues like an unpopular EU/IMF bailout as on local issues.

After falling in recent months, Greek bond yields have crept up again on fears that a new bout of political instability or a collapse of Samaras's government could unravel a feeble economic recovery taking root in the country after a prolonged recession.

Pollsters say the outcome of the first round could have an impact on the more crucial EU vote to be held next week, where polls show Samaras's New Democracy party lagging behind Syriza.

The focus on Sunday is on the race for Athens mayor, where the current mayor - a leftist-backed independent - is in the lead followed by candidates for Samaras's New Democracy party, rival Syriza and the anti-immigrant Golden Dawn.

A surprise second-place finish by Golden Dawn's spokesman Ilias Kasidiaris, who shot to fame after slapping a female lawmaker on live television, that allows him to go to the second round would pose a major setback for Samaras.

Samaras, a conservative who has promised Greeks that the country is finally pulling out of its economic crisis, has led a crackdown against the far-right party after a party sympathizer fatally stabbed an anti-fascist rapper last year.

The far-right party's leader and senior lawmakers are behind bars pending trial on charges of being part of a criminal organization, but the group consistently ranks as Greece's third or fourth-most popular party in opinion polls.

On Saturday, Samaras made a final appeal to voters to reject his rivals in the Athens race.