Ukrainian prime minister Yulia Tymoshenko is to launch a legal challenge against Sunday's presidential poll that unofficial results awarded to Viktor Yanukovych.
With 99 per cent of the votes counted the pro-Moscow Regions party candidate has 48.83 per cent of the vote to western-leaning Ms Tymoshenko's 45.59 per cent.
International observers, led by the Organisation for Security and Cooperation in Europe (OSCE), have praised the way in which the election was held, but Ms Tymoshenko's bloc has accused Mr Yanukovych's party of "falsification".
The prime minister, who has not appeared in public since Sunday's poll, reportedly told her party last night she would "never" accept the legitimacy of Mr Yanukovych's presidency.
As Mr Yanukovych's supporters gathered in Kiev to await the official announcement of the results, Serhiy Sobolev, a member of Ms Tymoshenko's bloc, told MPs in parliament: "Voting day displayed a cynical violation of Ukrainian law by the teams of Yanukovych, pressure on the electors and a broad arsenal of falsification by the Regions party.
"Consequently, the Tymoshenko bloc announces that we will defend in the courts our right, and the rights of our citizens, to honest and transparent elections."
The former prime minister was ousted from power in 2005's Orange Revolution, led jointly by Ms Tymoshenko and her former ally and incumbent president Viktor Yushchenko.
A failure to deliver on promises delivered five years ago and a breakdown of the pair's relationship has seen people become disillusioned with his pro-western leadership, analysts claim, with Mr Yushchenko only polling fifth in the first round of voting in January.
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