KIEV, Ukraine – Beating drums and chanting “resign,” supporters of apparent presidential winner Viktor Yushchenko blocked his election opponent from presiding at a Cabinet meeting yesterday as tensions persisted in this former Soviet republic.

Prime Minister Yanukovich showed no signs of cracking, refusing to surrender his post, and telling journalists he would challenge the results of Sunday’s runoff vote before the Supreme Court. Parliament passed a no-confidence vote for Mr. Yanukovich on December 1, but the law gives him 60 days to submit his resignation, and he has called Parliament’s move illegal.

“It is a matter of my principles not to submit a resignation,” Mr. Yanukovich said. “I know why they insist on that…they are shivering with fear.”

Mr. Yanukovich was declared the winner of a November 21 presidential vote, but hundreds of thousands wearing Mr. Yushchenko’s orange campaign color massed in Kiev, day after day, to protest election fraud. The Supreme Court eventually annulled the ballot, forcing Sunday’s rerun. Preliminary results showed Mr. Yushchenko winning easily.

Mr. Yanukovich wanted to preside at a Cabinet session yesterday, but about 1,000 protesters blocked the entrances to the government headquarters building. The ministers met later without Mr. Yanukovich at the Finance Ministry, said a spokesman for the finance minister, Vitaliy Lukianenko, and the deputy prime minister, Mykola Azarov.

“Shame on Yanukovich for clinging to power,” said a Kiev student and member of the pro-Yushchenko Pora youth movement participating in the protest, Stepan Lukyanov,

Yuriy Lutsenko, a lawmaker and member of the Socialist Party, which backed Mr. Yushchenko, said: “We did not blockade the Cabinet of Ministers. We blockaded only one person: Viktor Yanukovich.”

The protesters melted away by late morning after receiving guarantees that Mr. Yanukovich would not attempt to enter his office today.

The prime minister lashed out at outgoing President Kuchma, a one-time supporter, as well as Ukraine’s Parliament and the judicial system. He said they failed to prevent a “seizure of power – a scenario that was planned abroad, tested in Yugoslavia, Georgia, Romania, and has been applied in Ukraine.”

Mr. Yanukovich, who was supported by Russia’s government, draws his support largely from Ukraine’s east, where pro-Russia sentiment is high. Kiev and Ukraine’s west, where Ukrainian nationalist sentiment is strong, backed Mr. Yushchenko, a Western-leaning reformer.

Also yesterday, Mr. Yushchenko ally Yulia Tymoshenko traveled to Mr. Yanukovich’s hometown of Donetsk, where she answered hostile questions in a live TV appearance. She wore a Shakhtar Donetsk soccer club orange team T-shirt, telling the audience: “It is your color. It is our color.”

Ms. Tymoshenko has been tipped as one of the possible choices for the next prime minister. However, naming her to the job could worsen tensions because her radical rhetoric and calls for a seizure of power during the recent weeks of political crisis is anathema to Mr. Yanukovich’s supporters.

Mr. Yushchenko’s spokeswoman, Irina Gerashchenko, denied a report by the Interfax news agency that cited Mr. Yushchenko as saying he would propose Ms. Tymoshenko for prime minister. No decision on whom to propose for premier has been made, Mr. Gerashchenko said.