Five takeaways from Greece’s May 21 election

ATHENS, Greece—A crushing victory in Greece’s Sunday elections by the conservative New Democracy party of Prime Minister Kyriakos Mitsotakis will nevertheless lead to a new ballot in a month, as the winner fell short of a majority.

Here are five takeaways from the vote in the eastern Mediterranean country of 10.5 million people:

Huge win comes up empty New Democracy on Sunday scored its best result since 2007 at 40.79 percent, beating the leftist Syriza party of former premier Alexis Tsipras by over 20 points —the widest margin between the two leading parties in a Greek election since 1974.

But under a proportional representation electoral system introduced by Tsipras, New Democracy won 146 seats, five short of a majority in the 300-deputy parliament.

Mitsotakis himself on Sunday indicated he would decline a mandate to form a coalition government, and said parties should “speed up” procedures for a new ballot, expected for June 25 or July 2.

The new election will be governed by different rules granting the winner a seat bonus in parliament.

Left penalised Tsipras lost his fourth straight election to Mitsotakis after a campaign accusing the ruling party of “profiteering, inequality, nepotism, indifference, arrogance, injustice”.

Though the former premier who led the 2015 bailout negotiations that nearly crashed Greece out of the euro remains in charge of his party, the next election is do-or-die for his political future.

Another casualty Sunday was Tsipras’ former maverick finance minister Yanis Varoufakis, whose anti-austerity