President Viktor Yushchenko said today he had signed a decree dissolving the chamber and ordering a new election next month.
In a live television address after talks with party leaders Mr Yushchenko said it had been his "duty" to dissolve the assembly because it had violated the constitution.
Parliament, called into emergency session in anticipation of the announcement, appeared to ignore the decree. All present, including the president's arch rival, Prime Minister Viktor Yanukovich, backed a resolution affirming the chamber would continue to function and asking the cabinet to do the same.
The president, his powers cut by constitutional change after being swept to power by "Orange Revolution" protests in 2004, said all affairs in the country were "under control".
"I have signed a decree today to disband parliament. I have taken this decision in line with the constitution," Mr Yushchenko, seated at the table where the talks had taken place, told the country's 47 million people.
"My actions were prompted by a crucial need to preserve the state, its sovereignty and territorial integrity." The decree, released on the president's web site, said the new parliamentary election would take place on May 27th.
Mr Yushchenko said the snap election, barely a year after the last poll, "will be free. I solemnly guarantee this. An early election is needed to end the process of political infighting."
Mr Yushchenko has repeatedly clashed with the prime minister since reluctantly appointing him last August. He had repeatedly threatened to dissolve the assembly unless the three-party coalition backing the premier abandoned its practice of recruiting individual opposition members to join its ranks.
He told participants at more than six hours of talks that the country was "creeping towards a clear usurpation of power in a single pair of hands".
As the talks proceeded into the evening, Interfax news agency quoted a source in the Kremlin as saying Mr Yushchenko had asked Russian President Vladimir Putin to postpone talks scheduled tomorrow in Moscow.
Mr Yanukovich, defeated in the 2004 poll after the mass street protests, made a comeback last year on the strength of a 239-strong coalition in the 450-seat assembly.