Ukraine's Foreign Minister Borys Tarasiuk has quit after a long power struggle with PM Viktor Yanukovych.
Mr Tarasiuk is a close ally of President Yushchenko
He had been one of only two government ministers loyal to pro-Western President Viktor Yushchenko rather than his rival, Mr Yanukovych.
He was sacked by parliament in December but appealed against the decision.
He said he had been prevented from carrying out his duties properly by the governing coalition, which tried to dismiss him in November.
Mr Tarasiuk was one of Mr Yushchenko's closest allies in the 2004 Orange Revolution protests that propelled him to power.
Mr Yanukovych had called for Mr Tarasiuk's dismissal in November after a dispute between them over foreign policy.
Mr Tarasiuk appealed against his dismissal and won his case in a district court, but that verdict was overturned by the appeals court in Kiev, Ukraine's capital, on 10 January.
Earlier President Yushchenko had said his dismissal was illegal because it had not received his approval.
Under Ukraine's constitution, Mr Yushchenko is entitled to appoint the foreign minister.