ATHENS — Greek Prime Minister and New Democracy conservative party leader Kyriakos Mitsotakis are set to win Sunday's elections but are well short of the majority for an outright victory, an initial exit poll suggests.

Prime Minister Kyriakos Mitsotakis's party is heading for 36-40% of the vote. Predecessor Alexis Tsipras's center-left Syriza is well behind on 25-29%.

If neither party can form a coalition then Greek voters will return to vote in a second round in early July. The joint exit poll, by six polling agencies, was greeted with cheers at New Democracy headquarters in Athens.

However, experts have warned it may prove unreliable because many voters refused to reveal which party they had backed.

One of the big winners of the election appeared to be Syriza's socialist rival Pasok, which was predicted to attract 9.5-12.5% of the vote. That would make the party a potential kingmaker in coalition talks with both the center right and Syriza in the coming days.

Mitsotakis's center right has governed Greece for the past four years, and can boast that the country's growth last year was close to 6%. However, the election campaign was overshadowed by a rail tragedy in February that killed 57 people, many of them students.

Opposition parties highlighted the disaster as a symptom of a dysfunctional state that has been pared down to the bone after years of economic crisis and under-investment.

Four years ago winning 40% of the vote would have been enough to secure a majority in Greece's 300-seat parliament.

Now it requires more than 45%, because the winning party is no longer entitled to a 50-seat bonus in the first round, making a second round more likely.

Sunday’s vote was held under a proportional representation system which makes it difficult for any contender to secure an outright victory, setting the stage for a second round of balloting.

The cost-of-living crisis is the biggest issue for voters choosing 300 members of parliament.

Commentator Loukia Kotronaki, who researched youth opinions after a disastrous train crash that led to protests calling for governmental accountability, says there is “general distrust to all institutions” among young people.

“This lack of confidence is not to be translated into an intention to abstain from the elections because also a high percentage at 71 percent answered [a poll] they were going to vote in the election and would vote even if there is a second round,” she said..

But issues that are traditionally promoted by the right wing, including migration or Greek-Turkish relations, fall low on the list of priorities for young people while social issues, especially the cost of living, rank the highest, added Kotronaki.

Greece’s national broadcaster also revealed that the participation of Greek voters living in the United Kingdom reached 76.3 percent. In the capital, London, 2,904 people — out of 3,858 registered — cast their ballots, ERT said.

In the cities of Birmingham, Edinburgh, Glasgow and Leeds, 817 people — out of 978 registered — voted, it added. The voting took place without any incidents. — Agencies