A Russian-educated communist who once described the disintegration of the Soviet Union as "a crime against humanity" became the sixth president of Cyprus last night in an election seen as key to the reunification of the war-divided island.

Supporters waving red flags and Che Guevara banners poured on to the streets after Demetris Christofias, 61, clinched 53.4% of the vote in an unprecedented victory for the island's communist Akel party. By beating the conservative former foreign minister Ioannis Kasoulides, who polled 46.6% of the vote, he becomes Cyprus's first communist leader.

The result opens a new chapter in Cypriot politics with a younger generation of politician taking over the reins of government in a country that has remained partitioned since a coup aimed at uniting it with Greece prompted Turkey to invade in 1974. For the first time in the post-invasion era, Greek and Turkish communities will both be headed by leaders who are willing to negotiate - a prospect that has raised hopes of a settlement being reached.

In the run-up to the poll, Christofias, like Kasoulides, had repeatedly pledged to overturn the nationalist policies of the outgoing president, Tassos Papadopoulos, whose rejectionist approach to reunification had lead to the international isolation of the Greek Cypriots.

"My priority will be the salvation of this island, to reunify it with Turkish Cypriots under the umbrella of a bizonal, bicommunal federation," Christofias said before the election.

Yesterday's result showed that Greek Cypriots wanted a solution, despite voting against a 2004 UN plan outlining a federal union on the island, said Philippos Savvides, a political analyst. "If there is no serious attempt this year to secure a peace deal, the status quo and partition of the island will be solidified. It simply will be too late."

Christofias stands out among Greek Cypriot politicians for enjoying good relations with Turkish Cypriots including Mehmet Ali Talat, the president of the self-declared Turkish republic in the north. Without resolution of the Cyprus problem, Turkey - which has colonised the breakaway state with Anatolian settlers and maintains up to 40,000 troops there - has been told it will be unable to join the EU, a threat that has further raised the pressure.

The election of Christofias will cause concern in the EU and particularly in the UK, Cyprus's former colonial overlord. Although Christofias is a pragmatist keen to wield his pro-European credentials, he advocates a diluted form of Marxist-Leninism, demilitarisation of the entire island and is vehemently against the presence of its British sovereign military bases which he has called a "colonial bloodstain".

Some Cypriots voiced fears last night that the country's high standard of living would be endangered by the economic policies of a party that openly admires Cuba.