ATHENS, Greece (AP) -- After a most tantalizing of victories, having inflicted the heaviest defeat in half a century on the opposition, Greece's center-right Prime Minister Kyriakos Mitsotakis confirmed Monday that he would seek a second national election within weeks to secure the majority he needs to govern alone.
With 99.70% of the votes counted, Mitsotakis' New Democracy party won 40.79% -- twice the leftwing main opposition Syriza's 20.07% -- dominating 58 of the country's 59 constituencies. Socialist Pasok came in third at 11.46%, while turnout was 61%.
President Katerina Sakellaropoulou on Monday formally offered Mitsotakis the mandate to try and form a coalition government. But during a brief televised conversation, he told her he would return it within hours as there seemed no prospect of success. Mitsotakis voiced hope a new election could come as early as June 25.
ND's margin of victory far outstripped pollsters' forecasts and was the biggest since 1974, when Greece's first democratic elections were held after the fall of the seven-year military dictatorship.
Athenian Fotis Hatzos said that while he had expected ND's win, its hammering of the main opposition party took him by surprise.
"What is there to say, (Mitsotakis) destroyed them," he told The Associated Press. "He won fairly."
Markets welcomed what seems to signal the end of the political uncertainty that troubled the NATO and European Union member following the 2009 financial crisis, with the Athens stock exchange general index surging more than 7% at opening Monday and Greek bonds also rallying.
But the one-off proportional representation system in effect Sunday means ND only gains 146 of Parliament's 300 seats, five short of a governing majority. The new elections, expected no later than July 2, will revert to the previous system that grants the first party a bonus of up to 50 seats. That would ensure Mitsotakis a comfortable majority for a second term in power if Sunday's result holds.
The 55-year-old prime minister told President Sakellaropoulou Monday that he could see "effectively no way for the current parliament to form a government," overcoming the "obstacle" of the electoral system.
"That is why I will return the mandate to you this afternoon, so that we can head for new elections" if other parties fail to form a coalition deal, "as soon as possible, perhaps even on June 25," Mitsotakis said. "The country needs a strong and stable government with a four-year mandate and as soon as this is settled the better."
Mitsotakis had long suggested he would not seek a coalition partner whatever the election outcome.
Analyst Wolfango Piccoli, who has followed Greek politics for years, said voters prioritized the economy and political stability over everything else.
"ND's overwhelming performance is largely due to the positive track record on the economic front of the past four years," the senior political risk analyst at Teneo told the AP. "Syriza's inability to convey a coherent and credible economic plan also helped PM Mitsotakis and his ND."
"The outcome of yesterday's vote creates a window of opportunity for Greece to turn the page and move away from the toxic populist politics that emerged during" the financial crisis, he added.
When Mitsotakis hands back the mandate, it will then pass to Syriza leader Alexis Tsipras, and then to Pasok leader Nikos Androulakis -- neither of whom have any realistic chance of success. Each will have a maximum of three days to try to form a coalition. Once all options are exhausted, a senior judge will be appointed caretaker prime minister and new elections called.
Mitsotakis, a Harvard-educated former banking executive, came to power in 2019 on a promise of business-oriented reforms and has vowed to continue tax cuts, boost investments and bolster middle-class employment. His victory is widely expected to spur an upgrade of Greece's key credit rating to investment grade, which it lost during the financial crisis. That would strongly boost the country's ability to borrow from international markets, broadening its bonds' appeal to investors.
Mitsotakis has been credited with Greece's successful handling of the pandemic and of two crises with neighboring Turkey, while overseeing high growth and job creation after the end of the 2009-2018 financial crisis, but his term in office was tarnished by a wiretapping scandal and a railway disaster.
Tsipras, 48, called Mitsotakis on Sunday night to congratulate him.
"The result is exceptionally negative for Syriza," he said in initial statements. "Fights have winners and losers." Syriza gained 71 seats in Parliament.
Tsipras, who was prime minister from 2015 to 2019 -- riding a wave of anti-establishment feeling amid the financial crisis -- said his party would gather to examine the results and how they came about. "However, the electoral cycle is not yet over," he said. "We don't have the luxury of time. We must immediately carry out all the changes that are needed so we can fight the next crucial and final electoral battle with the best terms possible."
Tsipras transformed Syriza from a political minnow into Greece's main leftwing political pole during the financial crisis, when he won office pledging to reverse resented cutbacks dictated by international creditors. Instead, he was quickly forced to impose further financial pain in return for a new rescue loan.
Now, his political future is unclear, particularly if the forthcoming election confirms the trend set Sunday, when Syriza lost about 11 percentage points compared to its showing in 2019.
Pasok leader Androulakis, however, is buoyant, seeing his party claw back some of the ground it lost to Syriza in the crisis -- before which it traditionally dominated Greece's center-left.
Analyst Piccoli said the "devastating blow" suffered by Syriza and the failure of smaller leftwing parties to enter parliament "suggest that voters are determined to look ahead and leave behind the painful recent memories of the economic crisis."
"It remains to be seen whether Pasok will be up for the challenge of regaining a central role on the left side of Greek politics now that Syriza is on the backfoot," he said.