Ukraine's President Viktor Yushchenko has dismissed a constitutional court judge in what his opponents see as an attempt to prevent the body from ruling in the country's political crisis.

The president Thursday signed a decree dismissing Judge Volodymyr Ivashchenko for what he termed breaching his oath. The action was the third time in the past week that the president has dismissed a Constitutional Court judge.

The president's rival, Prime Minister Viktor Yanukovych, said the latest dismissal contradicts agreements he and the president made on solving a weeks-long political stalemate in Ukraine. Mr. Yanukovych appealed to Russia and the European Union to help salvage the fragile power-sharing deal between the president and the parliament.

The reformist president and the prime minister, who favors closer ties with Russia, reached a deal last week to hold early parliamentary elections aimed at ending the deadlock.

Mr. Yanukovych has called recent presidential decrees attempts to obstruct the functioning of the legislative and judicial branches of power.

The Russian Foreign Ministry responded that it was willing to consider Ukraine's specific proposal to mediate in the standoff.

Judge Ivashchenko has been a constitutional court judge since 2001 appointed to the post by former President Leonid Kuchma.

Tensions between the reformist president and the prime minister have been simmering since 2004, when the two men were rivals in controversial presidential elections.

Some information for this report was provided by AFP and AP.