Boisterous supporters of President-elect Viktor Yushchenko (search) blockaded the government headquarters on Wednesday, preventing the prime minister from convening a Cabinet session.

Yushchenko had called for the blockade after Prime Minister Viktor Yanukovych refused to concede defeat in Sunday's presidential election and late Tuesday appealed to Ukraine's Supreme Court.

About 1,000 demonstrators gathered at the government building early Wednesday, blocking off the entrances. People showing up for work were turned away.

"Resign! Resign!" the crowd chanted, banging on drums. Many wore ribbons and carried banners of orange, Yushchenko's campaign color. A few carried the red and black flags of Ukraine's Una-Unso, an ultranationalist group.

Protesters also gathered in a park nearby and on Kiev's (search) main square.

"We will show the criminal government that they cannot ignore the people's will," said one who gave only his first name, Vasil.

Later in the morning, Irina Lobanova, a spokeswoman for the Cabinet, said that the prime minister would not meet with his ministers as planned. Soon after the protesters began to disperse and near midday only a couple hundred remained outside the main entrance.

"We did not blockade the Cabinet of Ministers. We blockaded only one person: Viktor Yanukovych," said Yuriy Lutsenko, a lawmaker and member of the Socialist Party, which backed Yushchenko in last weekend's runoff.

Lutsenko said the protesters were given guarantees that Yanukovych would not attempt to enter his office Wednesday or Thursday. He said Yanukovych might hold the session outside Kiev, in which case there were no plans to try to stop him.

"We don't plan to follow Yanukovych all over the country," he said.

Yanukovych has remained defiant, submitting four appeals of the revote to the high court. The court was expected to decide later Wednesday whether to consider them, said Liana Shlyaposhnikova, a spokeswoman.

The opposition blockaded government buildings for weeks after the fraudulent Nov. 21 runoff, preventing Yanukovych and other officials from entering their offices. The country's high court annulled that ballot, forcing Sunday's rerun.

Oleksandr Ternavsky, Yanukovych's spokesman, called Yushchenko's move "completely illegal."

Ukraine's parliament passed a no-confidence vote in Yanukovych's government on Dec. 1 but the prime minister refused to resign. Ukrainian law allows his government to continue operating until a new Cabinet is in place, but no longer than 60 days.

Yushchenko won 51.99 percent to Yanukovych's 44.19 percent in Sunday's rerun of the vote, according to a final preliminary vote tally — a difference of about 2.3 million votes.

"In principle, we have the result," said Yaroslav Davydovych, the head of the Central Election Commission. "I don't know who can doubt it."

Yanukovych, who returned to work Tuesday as prime minister, said his campaign team had nearly 5,000 complaints about how the voting was conducted and claimed that 4.8 million people — more than double the margin of Yushchenko's victory — had been unable to cast ballots, among them disabled and elderly voters.

Ukraine's parliament approved restrictions on voting at home in a bid to prevent fraud, but the Constitutional Court threw out the restrictions on the eve of the vote. Many people, however, were unaware of the ruling, Yanukovych's campaign said.

The Council of Europe, the continent's top human rights watchdog, called on Yanukovych Tuesday to accept defeat. Unlike during the Nov. 21 vote, foreign monitors have said they saw no mass violations during Sunday's vote.

President Leonid Kuchma had urged both candidates to accept the official result.

The bitterly fought campaign frayed ties between the West and Russia. Yushchenko wants to bring the nation of 48 million closer to the West but the Kremlin is nervous about the eastward expanding EU and NATO.

Russian President Vladimir Putin personally campaigned for Yanukovych in the first two rounds of voting in November. He also had congratulated Yanukovych after the fraud-marred second round, ignoring western complaints that the vote was rigged.