Source of instability
Failure at the negotiating table would, in turn, halt Turkey's drive for European Union membership, cripple closer EU-Nato security co-operation and keep Cyprus as a source of instability on the EU's frontier with the Middle East.
Cyprus is already blocking parts of Turkey's EU membership negotiation process because of Ankara's refusal to recognise the Greek Cypriot government.
Cyprus was split into an internationally recognised Greek Cypriot south and a breakaway Turkish Cypriot north in 1974 when Turkey invaded after a short-lived coup backed by Greece.
The Turkish Republic of Northern Cyprus, with a population of 257,000, is recognised only by Nato-member Turkey, which maintains 35,000 troops there.
Cyprus joined the EU in 2004, but only the south's 800,000 Greek Cypriots enjoy membership benefits.
Eroglu has stressed he would continue negotiations if elected, although this would have to be under the twin sovereignty banner.
Campaigning on the last day outside his party headquarters in north Nicosia, Eroglu told thousands of supporters dressed in the campaign's orange colours that he expected a landslide victory on Sunday.
He pledged to keep Turkish Cypriots fully informed of developments in peace talks, saying that unlike Talat he was not negotiating "behind closed doors".
But Talat has warned that an Eroglu win would wreck the peace process and reinstate the international pariah status that Turkish Cypriots held before embracing a UN-brokered peace deal that Greek Cypriots turned down in 2004.
"The people are already convinced. They want a solution to the Cyprus problem," Talat told the Associated Press news agency after speaking to thousands of supporters at his final campaign rally, a few hundred metres away from Eroglu's gathering.
With fireworks exploding overhead and supporters' chanting "peace in Cyprus cannot be prevented", Talat said: "This is clear. So I'm sure that I will be re-elected and we will continue our journey to the world."