"The election results were falsified and cannot be grounds for distribution of deputy mandates. We believe the outcome is void and will demand a revote as some stations," Temir Sariyev told journalists.
Sariyev said his party has "proof of a large-scale fraud during the counting of votes," adding that the elections were "a crime on a national scale." He said other opposition parties reported their figures failed to match the official data.
He said the party would demand that "local authorities and members of election commissions be held criminally responsible for the fraud."
Opposition representatives reported that protests against the election results had started in the republic, with demonstrators blocking a highway linking the capital and a regional town. The Interior Ministry has not confirmed the information.
After 96% of the vote was counted, the Kyrgyz president's Ak Zhol party gained 48.82% of the vote in the elections, giving it all parliamentary seats, according to the Central Election Commission.
In line with the current provisions, parties have to win at least 5% of the national vote and overcome a 0.5% threshold in each of the Central Asian state's regions to be elected to the one-chamber, 90-seat parliament.
But the Supreme Court of Kyrgyzstan revoked Tuesday a decision by the Central Election Commission on the 0.5% regional voting threshold, satisfying an appeal earlier by the Ak Zhol party. The decision will mean that opposition party Ata-Meken that gained 8.7% of the vote is likely to receive parliamentary seats.
The Ak Zhol party earlier appealed the Central Election Commission's decision on the 0.5% regional threshold saying the percentage should be counted proportionally in line with the number of voters in each region, and not on an equal basis for all of the country's regions, as the commission demanded.
President Kurmanbek Bakiyev called the early vote in October, after changing the Constitution in a referendum that strengthened his powers and also established his own Ak Zhol party. In line with the new Constitution, parliament was elected from party lists for the first time in the ex-Soviet state's history.
Bakiyev's opponents said the Constitutional changes and the early parliamentary elections were initiated by the president to usurp power and backtrack on democracy. However, Bakiyev's supporters say the new system is more democratic.
Kyrgyzstan has been in political turmoil ever since 2005 when disputed parliamentary elections triggered mass protests that ousted the longtime leader Askar Akayev and brought Bakiyev to power.
The opposition accuses Bakiyev of failing to improve living standards, curb corruption and bring democracy to the country. The opposition had also accused authorities of plotting "large-scale vote rigging" at the parliamentary elections.
The Organization for Security and Cooperation in Europe said the elections had failed to meet OSCE commitments.
