Yushchenko appointed Yuriy Yekhanurov, a former economics minister and regional governor, as acting prime minister, and addressed the nation in an effort to quell the worst political crisis in his young term. But the mass dismissal signaled the end of the broad coalition that successfully led a popular revolt after fraudulent presidential elections late last year and ultimately ushered Yushchenko into power.

"I knew that there were definite conflicts between those people. ... I hoped that if each of them immersed himself in work, there would not be enough time for mutual intrigues, for PR and anti-PR campaigns between certain political forces of a single coalition," Yushchenko said after the failure of a last-ditch effort Wednesday to impose unity on the Tymoshenko government and his own presidential administration. "I want people to feel that the government works in harmony ... [but] they lost the team spirit and faith."

The dismissal of the government was triggered by a series of resignations by top officials who charged that some of the most powerful people around Yushchenko were using their government positions to enrich themselves and spoiling one of the deepest promises of December's popular revolt: the eradication of endemic graft.

On Saturday, Oleksandr Zinchenko, Yushchenko's chief of staff, accused by name Petro Poroshenko, the head of the Defense and Security Council, and Olexander Tretyakov, a senior presidential adviser, of "cynically carrying out their plan to use government posts to their own ends."

"Corruption is now even worse than before," said Zinchenko, while announcing his resignation in front of television cameras.

Political analysts said the crisis stemmed in large part from the political enmity between Poroshenko and the prime minister, Tymoshenko.