Zimbabwe's prime minister has filed a lawsuit against President Robert Mugabe, alleging he violated the constitution and a power-sharing deal.
Morgan Tsvangirai petitioned the High Court to nullify Mr. Mugabe's appointment last month of 10 provincial governors.
Mr. Tsvangirai accused Mr. Mugabe of not consulting him about the appointments as required under the power-sharing agreement.
President Mugabe's office did not immediately comment on the accusations.
Last month, Mr. Tsvangirai's MDC party rejected the appointment of several ambassadors, accusing Mr. Mugabe of violating the power-sharing deal. The president insisted the appointments are legal.
Mr. Mugabe and Mr. Tsvangirai formed a fragile and frequently-troubled unity government following the disputed 2008 elections.
President Mugabe recently called for an end to the coalition and for new elections next year. He said things happening within the coalition are "foolish and stupid" and that the power-sharing deal should not be renewed when it expires in February.
Mr. Mugabe has ruled Zimbabwe since the country won independence from Britain in 1980. Western countries accuse him of driving Zimbabwe to ruin with years of political repression and economic mismanagement, especially the seizure of white-owned commercial farms.
Mr. Mugabe blames the problems on interference from Britain and its allies.
Some information for this report was provided by AP.