Zimbabwe’s opposition leader has threatened day to pull out of the national unity Government after learning that Robert Mugabe had awarded all top Cabinet posts to members of his own party.

“An idiot wouldn’t accept that,” an angry Morgan Tsvangirai, the leader of the Movement for Democratic Change (MDC), said. “That’s not power sharing, it’s power grabbing.”

Thabo Mbeki, the former South African President, who mediated the power-sharing deal between the MDC and President Mugabe’s Zanu (PF) party last month, was due to fly to Harare today to salvage the agreement, which was meant to break the country’s long political impasse.

At the weekend Mr Mugabe gave Zanu (PF) every important ministry, including defence, home affairs — which controls the police — justice, foreign affairs and local government, but said that he was prepared to discuss the finance ministry.

Mr Tsvangirai, whose party won the parliamentary elections earlier this year and the most votes in the first round of the presidential ballot, hit back. It was “not negotiable” that the ministry of home affairs should be taken out of the MDC’s hands, he declared.

When Mr Mbeki arrives on Monday, Mr Tsvangirai said that: “we shall negotiate until agreement is reached. But that doesn’t mean we will compromise. If we don’t have the instruments of change in this agreement, then it is stillborn. That will be the end of it. We will go our different ways.”

Mr Tsvangirai was speaking at a rally of 15,000 supporters in a township football stadium, surrounded by piles of uncollected rubbish and suffused by the stench of sewage from burst drains. It was the first large gathering that he had been able to address without disruption in seven months.

“No, Robert Mugabe, stop that,” Mr Tsvangirai said. “We are not going to be part of such an arrangement.”

Mr Mugabe can now be expected to drive his unilateral Cabinet through as a fait accompli. MDC officials said that they would not be surprised if Mr Mbeki, who has been accused of siding with Mr Mugabe, endorses the selection of ministries.

The MDC’s last hope after that is that the Southern African Development Community, the 14-nation regional political alliance that convened the talks, will reject what observers describe as a coup. Although Mr Mugabe’s support in the grouping has dwindled, it is seen as unlikely that they would all turn against him.

Mr Mugabe may only be delaying the inevitable, as Zimbabwe faces a famine, economic collapse and the demise of the health and education systems.

“Zimbabwe is closer to the tipping point than ever before,” said a Western diplomat. “The legendary stoicism of the Zimbabwean people has never been tested like this. Mugabe may have overplayed his hand.”

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