Viktor Yushchenko signed the parliament dissolution order after hours of crisis talks with parliamentary leaders failed to produce a compromise decision. He accused the majority coalition, led by Prime Minister Viktor Yanukovych, of trying to expand its power base by unconstitutional means, notably by taking in individual lawmakers. Under the law, only entire factions can join the coalition.
But Speaker Oleksander Moroz said the president had no legal grounds to disband the assembly.
The snap polls, set for May 27, are another attempt by Yushchenko to resolve the country's ongoing political crisis, which has faced Ukraine since the latest ballot in March 2006.
At the weekend, supporters of both sides took to the streets in central Kiev in mass rallies. Yushchenko's backers urged him to dissolve parliament while protesters from the Yanukovych camp said they would dispute the legality of such a move with the Constitutional Court.
