Zimbabwe's opposition Movement for Democratic Change (MDC) says talks with President Mugabe have failed to produce agreement on cabinet posts.
MDC spokesman Nelson Chamisa accused Mr Mugabe of demanding all the key ministries for his Zanu-PF party in the new unity government.
He was speaking after a meeting between MDC leader Morgan Tsvangirai and the Zimbabwean President.
A power-sharing deal was signed two weeks ago to end the political crisis.
Mr Chamisa said the opposition and Mr Mugabe remained far apart on the issue of who should control which ministries.