KIEV: Prime Minister Yulia Tymoshenko pledged Thursday to bring Ukraine into the EU within five years if she wins this weekend's presidential polls, as she moved to play up differences with her main rival.

In a keynote address in Kiev, Tymoshenko painted Sunday's vote as a stark choice between herself and her main opponent Viktor Yanukovich, who is leading the polls and is seen as a pro-Russian figure.

Incumbent Viktor Yushchenko, who led the 2004 Orange Revolution that swept the old order from power, had vowed to bring Ukraine into the European Union but his plans fell apart amid political instability and bitter public disappointment.

"Ukraine must become a member of the European Union and for me that is a priority. I will do everything so that during my presidency Ukraine becomes a member of the EU," Tymoshenko said.

Ukraine's presidential mandate is for five years.

Making her clearest commitment yet of the campaign to European integration, Tymoshenko said an association agreement should be signed with the European Union this year, as well as an accord on the creation of a free trade zone.

The elections are taking place amid a severe economic crisis and disillusionment with the results of the Orange Revolution, which sparked hopes of a new era of reform in Ukraine and was strongly supported by Tymoshenko.

Opinion polls show Yanukovich with a lead of around 10 percent ahead the elections.

However with 18 candidates standing, a February 7 run-off is almost certain and analysts believe the prime minister still has a chance of making up ground by then.

Tymoshenko has traditionally been seen as a pro-EU figure although the warmth of her relationship with Russian Prime Minister Vladimir Putin in the last months has led analysts to conclude she has drawn closer to Moscow.

Her former ally Yushchenko is expected to be punished at the ballot box for the failure of the Orange Revolution to bring about major economic and political reform, falling at the first hurdle with a weak single-digit showing.

Wearing her trademark golden hair braid and a cream dress, Tymoshenko also launched a new attack on Ukraine's super-rich oligarchs, who own much of the country's industry and many of whom have close links to Yanukovich.

"There are two paths. Strengthen the oligarchs, personified by Yanukovich. Or the other path -- the creation of an independent state," she said.

She vowed to improve relations with Russia that have collapsed under Yushchenko, stating that Kiev-Moscow ties should be "peaceful, constructive but very strict and pragmatic".

The prime minister, her voice hoarse from weeks of campaigning, took questions after her speech on video link from supporters ranging from miners to folk singers.

A day earlier, Tymoshenko had accused Yanukovich of seeking to organise election fraud from his powerbase in the east of the country. But he hit back Thursday with a bitter personal attack on his rival.

"This is her way of life. This is how she lives. We have got used to it," he said on a campaign visit to the northeastern city of Kharkiv, quoted by the website of his Regions Party.

Yanukovich said that with a high turnout he even had a chance of outright victory in the first round.

Adding uncertainty to the situation, a new poll from a Russian research organisation showed Yanukovich well ahead but with a lesser-known candidate pushing Tymoshenko into third place.

Yanukovich will poll 30.5 percent of the vote while former economy minister and banking executive Sergiy Tigipko would win 14.4 percent, compared with 13.9 for Tymoshenko, the poll for the Russian Public Opinion Research Centre showed.

While Tigipko may be benefiting from being a relatively fresh face, polls by other Ukraine-based organisations published over the New Year showed him posting a far weaker vote.