The decree signed by Viktor Yushchenko on Monday became effective after it was published in a state newspaper on Tuesday. The Supreme Rada was dissolved to allow snap elections after the government coalition collapsed.
Yushchenko reopened parliament indefinitely in order it approve laws "to overcome negative effects of the global financial crisis" and amend the budget accordingly.
Yushchenko also postponed early elections from December 7 to December 14.
However, the party of Prime Minister Yulia Tymoshenko, once Yushenko's ally and now opponent, declared on Tuesday its opposition to the December 14 date for the election.
"The elections will not take place on December 14," the UNIAN news agency quoted the Tymoshenko Bloc's deputy head Andriy Portnov as saying.
Accusing the president's order of threatening Ukraine's economic destruction, Portnov said the bloc would "take all possible legal steps to ensure the election does not start on December 14."
The president dissolved the legislature on October 9 after the collapse of the ruling "orange" coalition of his Our Ukraine bloc and prime minister's alliance over a host of differences. Political groups have failed to form a new coalition, but Tymoshenko's supporters are working to prevent new elections from taking place.
