Europe's fourth largest country, Ukraine, is sliding into a potentially cataclysmic political crisis over allegations that President Leonid Kuchma is guilty of massive corruption, electoral fraud and conspiracy to commit murder.

The president's foes--an unusual coalition of Communists, democrats and right-wing nationalists--have held almost daily protest rallies over the past several months. On several occasions, crowds numbering more than 10,000 have surged through the streets of Kiev demanding Kuchma's resignation over tape recordings that purport to show him planning the murder of opposition journalist Georgiy Gongadze.

Kuchma has lashed out at the demonstrations as "psychological warfare" and "a direct

On March 9, 10,000 people took to the streets of Kiev demanding Kuchma's resignation. SERGEI SUPINSKY/AFP

threat to Ukraine's national security," and has warned that he is ready to mobilize the security forces to "defend constitutional order."

Police violence against protesters has escalated sharply in recent weeks, including a brutal raid on the opposition's downtown Kiev tent camp in early March, which resulted in many injuries and dozens of arrests.

Gongadze's headless corpse was found half-buried in a forest near Kiev in November. He had been an editor of a crusading Internet newspaper, Ukrainskaya Pravda, which specializes in documenting corruption accusations against government officials.

In February, prosecutors verified the corpse as that of Gongadze and launched an official investigation into his murder. Kuchma, who won post-Soviet Ukraine's only free and open presidential election in 1994, has consistently and emphatically denied any involvement in the journalist's fate.

But the 300 hours of secret tape recordings, publicly released in late 2000 by parliamentary opposition leader Oleksandr Moroz, suggest otherwise. Former presidential bodyguard Mikola Melnychenko--who has since fled abroad--recorded the obscenity- peppered conversations, apparently by means of a taping device hidden under a sofa in Kuchma's office.

The Melnychenko tapes seem to contain enough dirt on Kuchma to launch a dozen impeachment trials. Among other explosive revelations, Kuchma is allegedly heard telling security officials that Gongadze should be made to "disappear," perhaps by having him kidnapped by "Chechen bandits."

In sections recorded during the president's re-election campaign in 1999, Kuchma orders aides to threaten local leaders and factory directors with arrest on corruption charges if they don't bring in enough pro-Kuchma votes. "We need to win by a comfortable margin," the voice says.

In another conversation, Kuchma is heard railing against a Ukrainian judge who was "too lenient" with a lawyer accused of spreading false information about the president. "You take this judge out and hang him by the balls," Kuchma allegedly shouts.

Kuchma has not denied that the voice on the tapes is his, and has confessed that he often uses "salty language" in private, but has repeatedly insisted that crucial sections of the recordings were "doctored" by his enemies. Several others whose voices are heard on the tapes, including parliamentarians and officials, have verified their participation in those conversations.

However, a two-month examination of the recordings by the International Press Institute in Vienna ended inconclusively in early March with experts unable to determine if the digitally recorded tapes had been altered.

Ukraine largely has disappeared from the world's radar screens since it gained its independence from the USSR a decade ago. Fearful of pushing Kiev into Russia's embrace, the West has tended to downplay the growing signs that Ukraine's post-Soviet democracy is slipping off the rails.

Critics warn that Kuchma, a former Soviet rocket factory director with strong ties to Moscow, is maneuvering to curb the powers of Ukraine's parliament and set up an autocratic "presidential republic," following the examples of Boris Yeltsin's violent crushing of his opposition legislature in Russia in 1993.

The crisis has given new life to Ukraine's parliamentary opposition, which has warned it will begin impeachment proceedings if prosecutors file criminal charges against the president. However, the crisis ultimately may be resolved in the streets. Although the protests against Kuchma have yet to attract mass public participation, most of the country's usually fractious opposition leaders appear to have thrown in their lot with the burgeoning "Ukraine Without Kuchma" movement, including Yulia Tymoshenko, a liberal economist and wealthy business tycoon whom Kuchma fired from her post as deputy prime minister in January, and later had arrested on charges of embezzlement and fraud. Tymoshenko has become the chief poster girl of the anti-Kuchma opposition and, some say, its main political force. From her cell in Kiev's Lukyanivka prison, "Iron Yulia" continues to issue a stream of statements and directives to her followers.