Shortly after he enters office, the new president of Greek Cyprus will face a crucial, difficult decision that will help determine the divided island's fate.

Whoever wins elections Sunday must choose between accepting or rejecting a hotly debated United Nations plan to reunify Cyprus. The issue has become the central issue in Sunday's election.

The election comes 10 days before U.N. Secretary-General Kofi Annan is to visit Cyprus in a last-ditch bid to break a prolonged deadlock and win acceptance of his plan by Feb. 28.

Cyprus has been divided into a Greek Cypriot-controlled south and a Turkish-occupied north since Turkey invaded in 1974 in the wake of an abortive coup by supporters of union with Greece. A breakaway Turkish Cypriot statelet in the north is only recognized by Turkey, which maintains 40,000 troops there.

Alvaro de Soto, Annan's special envoy for Cyprus, returned to the island late Friday after talks in New York with the U.N. leader, warning that if the plan is not accepted by the deadline "the opportunity (for a settlement) disappears until something happens, and that is totally uncertain."

If the deadline is not met, only the Greek-backed portion of Cyprus will be able to sign its EU accession agreement by April 16.

The Annan plan envisages reunification as a single state consisting of two separate Greek and Turkish Cypriot "component states" linked through a weak central government.

Ten candidates are running in the election, but the duel is between Glafcos Clerides, the 83-year-old right-wing incumbent, and Tassos Papadopoulos, 69, a centrist backed by other opposition leftist parties.

Clerides decided to run for a third term, but limited to 16 months instead of a full five years, saying he is best qualified to continue the delicate reunification negotiations. The opposition accuses him of being too old and willing to yield on basic issues of principle.

Greek Cypriots are deeply split over the plan.

Turkish Cypriot leader Rauf Denktash, who is backed by Ankara, opposes the Annan plan because it rejects his demand for recognition of his statelet as a prelude to reunification as a two-state confederation.

Polls give Papadopoulos between 45 and 48 percent, compared to between 34 and 38 percent for Clerides. Both would be short of the 50 percent result needed for victory in Sunday's first round, making a second round between the two leading candidates likely.

Clerides' chances have suffered because his closest aide in the negotiations, Attorney-General Alecos Markides, is also running for the presidency. The latest polls, however, give Markides only 8 percent.