The party of Ukrainian Prime Minister Yulia Tymoshenko is demanding a recount of ballots in Sunday's presidential polls, which were narrowly won by opposition leader Viktor Yanukovych.
"We demand that the votes be recounted and the results declared invalid," MP Oleg Lyashko was quoted as saying by the Ukrainian news agency Unian.
International monitors have praised the elections.
Tymoshenko has stayed out of the public eye since Sunday after earlier vowing to take her supporters to the street if she believed the polls had been rigged. She also called off a news conference originally scheduled for Monday.
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