Ukraine's two presidential candidates have staged their final rallies ahead of the February 7 2010 run-off election, while authorities have increased security amid rising fears of unrest, the Voice of America said.

Prime minister Yulia Tymoshenko and pro-Russian opposition leader Viktor Yanukovych ended a bitterly-fought campaign on February 5 with rival rallies just blocks away from each other in the capital, Kyiv.

Tensions have mounted in recent days with each side accusing the other of plotting to rig the election.  If the margin of victory is close, there is growing evidence the loser will refuse to accept defeat and attempt to mobilize supporters on the streets.

Yanukovych appeared confident as he waved to a crowd of supporters from a concert stage in a central Kyiv square, accompanied by a victorious fanfare, Radio Free Europe/Radio Liberty said.

The former mechanic from Ukraine's Donbass mining region, seen as close to Moscow, won by a 10 per cent margin in the first round on January 17. Polls give him a narrow victory over Tymoshenko after a bitter campaign full of smears and insults.

An electoral victory would represent a dramatic reversal of fortune for Yanukovych, whose election as president five years ago triggered the mass Orange protests and threw out his win on grounds of fraud.

Addressing the crowd in Russian, he predicted the end of the Orange era that propelled Tymoshenko and President Viktor Yushchenko to power in 2004.

"February 7 will be the last day of the Orange era," he declared. "Five years of Orange rule have made it clear to the Ukrainian people that we can no longer live this way. On January 17, the majority of Ukrainians voted for a free Ukraine without the Orange people."

Tymoshenko, one of the key figures in the Orange revolution, stood humbly alongside religious leaders, asking for forgiveness for the failings of her government but promising her values had not changed, euronews reported.

"I am appealing to God to bless the unity of our state, so that nobody will divide us anymore or make us enemies," she said.

The Kyiv Post has a portrait of the contestants.