Talk Radio 702 reported last night that Mugabe discovered the intentions of his security forces.
He immediately flew back after being warned that the generals, who have kept him in power for 28 years, were in the process of taking things into their own hands.
During the March elections, the generals and police heads vowed they would never accept Executive Prime Minister designate Morgan Tsvangirai as the head of state.
Mugabe and MDC leader Tsvangirai are expected to meet soon to iron out some outstanding issues pertaining to the inclusive government.
"It can happen anytime. It could happen today or tomorrow. But it depends on the outstanding differences," said MDC spokesman Nelson Chamisa.
Mugabe has said the new government would be announced by the end of the week.
However, he stressed there would be no reversal of his nationalisation programme, and that land seized would never be returned to farmers who had fled to "Australia and South Africa".
In the meantime, the MDC shot down Mugabe’s claim of the imminent finalisation of the inclusive government.
"Mugabe obviously knows something that I do not. We have a deadlock, and our positions are tangential," said MDC secretary- general Tendai Biti.
He added: "As far as we know, there was no agreement on anything."
According to Biti, a constitutional amendment still had to be drafted to give legal effect to the power-sharing deal.
"Also, importantly, constitutional amendment number 19 still has to be drafted. Without it there is no legal foundation of the government," said Biti.