The court issued its verdict in response to an appeal by the pro-Western Yushchenko, who said the 21 November runoff had been rigged in favor of Kremlin-backed Prime Minister Viktor Yanukovych.
Yushchenko told tens of thousands of people in the center of Kyiv that the opposition has won: "Today, the Supreme Court of Ukraine put an end to the discussion whether Ukraine will have a revote [of the second round of presidential elections] or a new election which Leonid Kuchma wished for. We have won."
He continued: "Today, I want you to give special applause to the judges of the Supreme Court. They are true heroes today. We demand that the Central Election Commission be dismissed. These people betrayed their oath, betrayed millions of Ukrainians. They should be dismissed."
Yushchenko also urged outgoing President Leonid Kuchma to fire the government. The court chairman, Anatoliy Yarema, who delivered the ruling, said a repeat of the runoff election was required to take place by 26 December.
The court's ruling rejected arguments from government lawyers that an entirely new election be held. Stepan Gavrich, a Yanukovych representative, criticized the decision, saying the court "effectively played a political role."See Ukraine's Disputed Election for more RFE/RL coverage of Ukraine's presidential election.