Heads of EU nations' parliaments called on Ukraine on Saturday to calm the political tension which has reigned in the country since President Viktor Yushchenko dissolved parliament in April.

They made the call at a conference of the EU parliament speakers in the Slovak capital of Bratislava, reports reaching here said.

Ukrainian political leaders should settle the mounting political tension in a way that would be in harmony with standard democratic principles, thus avoiding possible radicalization of society, the heads of parliament said in a statement.

Slovak parliament speaker Pavol Paska said Europe's acceptance of Ukrainian leaders after democratic elections will depend on their further steps.

"The main thing is whether the will to wield power and to use any instruments for this purpose, or citizens' will to have a democratic state, will prevail in the groups arising from the democratic struggle," Paska said.

Ukraine's political turmoil began in April, when Yushchenko signed decrees dissolving parliament and calling early elections.

The dissolution order triggered weeks of debates and demonstrations between supporters of the president and those of Prime Minister Viktor Yanukovych, who insisted that the act was unconstitutional.

The political situation was further complicated when Yushchenko sacked three judges of the country's constitutional court between April 30 and May 10, as the court started legal proceedings on the legitimacy of the president's decrees.