Greek conservative opposition leader Kyriakos Mitsotakis has comfortably won a parliamentary election as voters rejected Prime Minister Alexis Tsipras after a tumultuous four years.

With more than 80 per cent of votes counted, Mitsotakis’ New Democracy party had 39.7 per cent of the vote compared to Tsipras’ left-wing Syriza party at 31.6 per cent on Sunday.

The extreme right-wing Golden Dawn, founded by neo-Nazi supporters, teetered just below the three per cent threshold needed to enter parliament, a massive fall of support for a party that had become the third largest in the Greek legislature during the country’s financial crisis.

The results indicated that Greek voters were bucking a recent trend in Europe of citizens rejecting the political mainstream and turning to populist and eurosceptic parties.

“I asked for a strong mandate to change Greece. You offered it generously,” Mitsotakis said in his victory speech.

“From today, a difficult but beautiful fight begins.”

Mitsotakis, 51, vowed to abide by his campaign pledges to cut taxes, attract investment and improve the job market.

He had been ahead in opinion polls for three years and managed to build a sizeable lead.

“Greeks deserve better and the time has come for us to prove it,” he said.

Tsipras conceded defeat and said he phoned Mitsotakis to congratulate him.

“The citizens have made their choice. We fully respect the popular vote,” Tsipras said in a speech from central Athens.

He said his party now would work to protect the rights of working Greeks as “a responsible but dynamic opposition” to the government.

The election was the first held since Greece emerged from three international bailouts that were dependent on successive governments implementing strict austerity measures, including major tax hikes and spending cuts.

The financial crisis saw unemployment and poverty levels skyrocket and the economy shrink by a quarter.

Mitsotakis, the son of a former prime minister, brother of a former foreign minister and uncle to a newly elected mayor of Athens, fought during the campaign to shed the image of family privilege.

He pledged to make Greece more business-friendly, attract foreign investment, to modernise the country’s notorious bureaucracy and to cut taxes.

Tsipras, 44, called the election three months ahead of schedule after Syriza suffered a severe defeat in EU and local elections in May and early June.

He had led his small Coalition of the Radical Left, or Syriza, party to power in 2015 on promises to repeal the austerity of Greece’s first two bailouts.

But after months of tumultuous negotiations with international creditors that saw Greece nearly crash out of the EU’s joint currency, he was forced to change tack.

He signed up to a third bailout and imposed the accompanying spending cuts and tax hikes.

Tsipras also cemented a deal with neighbouring North Macedonia under which that country changed its name from plain “Macedonia”.

Although praised by Western allies, the deal angered many Greeks, who consider use of the term harbours expansionist aims on the Greek province of the same name.