[JURIST] Ukrainian Prime Minister Viktor Yanukovych [BBC profile] and leaders of the Ukrainian Parliament filed a lawsuit Tuesday seeking to block a decree from Ukrainian President Viktor Yushchenko [official website; BBC profile] to dissolve parliament and hold elections in May. Yushchenko issued the decree [statement] Monday, saying that his "actions are dictated by the crucial necessity to save the country's sovereignty and territorial integrity, and to ensure the adherence to the constitution and the observance of civil rights and freedoms." Yushchenko accused the country's parliament, the Verkhovna Rada [official website], of "deliberately escalating" the latest political crisis [BBC Q&A] in the country, saying there are three "dangerous tendencies" in the parliament:

The first one is the unconstitutional process to form and expand the parliamentary coalition. Under the constitution, the coalition can be formed by deputy factions and not by individual or group members. Any other way is a revision of the will of the nation and the most cynical challenge for each of us.

The second tendency is the practice to pass illegitimate and unconstitutional laws. The most recent example is the Law on the Cabinet of Ministers, which systemically violates the constitution of Ukraine and is an attack on Ukraine's constitutional order.

The third tendency is their inability to fulfill obligations and fraudulent policy of intrigues and betrayals disguised as national unity slogans….

Violations of the Constitution of Ukraine, the biggest of them being the unconstitutional way of coalition formation, created obvious legal and political reasons to dissolve parliament.

Yushchenko acknowledged that calling new elections was "extreme" but said that he was obliged to act under the Ukrainian constitution [text]. The president pledged that the parliamentary elections would be "held in accordance with Ukraine's constitution, as well as the national and international standards of democracy."

Yanukovych, Yushchenko's political rival, and top legislators have filed an appeal [Reuters report] with the Ukrainian Constitutional Court [official website], asking for a ruling within five days. The prime minister has indicated that members of parliament's majority coalition will continue to meet in the parliament hall pending a decision from the court. Parliament has also voted to fire the current Central Elections Commission of Ukraine [official website] and reinstate the previous commission, and the majority has said that the funding necessary to hold elections will be withheld. Yushchenko called the vote to reinstate the previous commission "unlawful" and "immoral" [press release]. The previous commission was accused of fraud [JURIST report] in the 2004 presidential election which brought Yushchenko to power. Bloomberg has more. AP has additional coverage.

Yushchenko and Yanukovych were fierce rivals in the 2004 presidential election [JURIST report], the results of which were invalidated by the country's Supreme Court [JURIST report] following fraud allegations. Yushchenko was sworn in as Ukraine's president [JURIST report] in January 2005 on the wings of the populist Orange Revolution [BBC timeline] after winning a re-vote. Yushchenko reluctantly accepted Yanukovych as prime minister last June and the two have since clashed over parliamentary attempts to expand the cabinet's power [JURIST reports] at the expense of the presidency.

1:57 PM ET – The Constitutional Court has agreed to hear the appeal. Itar-Tass has more.