Demetris Christofias, the Cyprus Communist party leader, won a run-off presidential vote by a clear margin on Sunday, opening the way for fresh negotiations on re-unifying the island’s Greek and Turkish communities.

Yiannakis Kassoulides, the rightwing candidate, conceded defeat an hour after the polls closed. With 97 per cent of the vote counted Mr Christofias was leading with 53.5 per cent to 46.4 per cent – a result that makes him the first unreconstructed communist to head a European Union member-state.

Mr Kassoulides, a European parliament member and former foreign minister backed by the right-of-centre Democratic Rally party came first in last Sunday’s first-round poll. But he lost ground amid bitter political infighting at the end of the campaign.

Mr Christofias is committed to reviving UN-backed talks on re-unifying the Greek and Turkish communities on Cyprus as soon as possible, although he has avoided giving details during the campaign of how a peace settlement might be reached. Mr Kassoulides on Sunday said he would support the new government’s efforts to find a solution.

Bi-communal negotiations stalled under the presidency of Tassos Papadopoulos, a hardline nationalist who was eliminated in last Sunday’s vote. Mr Papadopoulos persuaded Greek Cypriots to reject a UN peace plan at a referendum in 2004, held two weeks before Cyprus entered the EU – a result that prevented the Turkish Cypriot community from enjoying the benefits of accession.

Mr Christofias finished second last week by a margin of just 0.2 per cent, after Mr Kassoulides captured a majority of votes cast by Greek Cypriot students returning from Greece and the UK.

His prospects improved when the nationalist Democratic party, formerly headed by Mr Papadopoulos, which is supported by 15 per cent to 17 per cent of Greek Cypriot voters, decided to back the communists at the run-off poll.

Markos Kyprianou, Cyprus’s European commissioner, had persuaded fellow-executives in the Democratic leadership to back Mr Kassoulides. But members of the 200-strong central committee overturned the decision amid threats, insults and a fist-fight among party officials.

Mr Christofias, aged 59, a Moscow-educated populist who is the first communist to run for the Cyprus presidency, appears to have given up his eurosceptic views. He re-invented himself during the campaign as a champion of EU citizens’ rights, saying “We shall become ‘Euro-fighters’ struggling on behalf of the poor.”

Although the communists still embrace Marxism-Leninism, the party controls a wide range of businesses, including an investment company listed on the small Nicosia stock exchange.