But Mr Tsvangirai stressed his commitment to a controversial power-sharing deal that, he says, has "restored the hopes of the people" writes Jane Fields in New Scotsman.

Sitting under a mango tree in the eastern city of Mutare yesterday, the Movement for Democratic Change (MDC) leader insisted the deal had brought peace to a country wracked by nearly a decade of economic and political turmoil.

"It's frustrating that some of the issues are not moving as fast as we would wish," he said. "But overall I think that the inclusive government has achieved stability."

Zanu-PF and the MDC are set to go head-to-head in a crunch meeting today. The MDC is unhappy that Mr Mugabe is refusing to budge on the appointments of central bank chief Gideon Gono and attorney general Johannes Tomana, alleged to be behind the recent prosecutions of several MDC MPs.

Zanu-PF's top decision-making body, the politburo, has told Mr Mugabe to take Mr Tsvangirai to task on the issue. Asked about his relationship with the president, whose police brutally beat him on the head at a prayer rally in 2007, Mr Tsvangirai said the pair were trying to co-operate. "I think we have tried at a personal level to reduce competition and concentrate on trying to ensure that this inclusive government does not slide back," he said.

He added that remnants of mistrust were only natural "among people who had been polarised for so long".

In the past six months Zimbabwe has changed almost beyond recognition. Month-on-month inflation is now 0.6 per cent (previously, annual inflation topped 500 billion per cent) and once-empty shop shelves are stuffed with South African imports. In a highly-significant move, Mr Tsvangirai was saluted by army chiefs at last week's Defence Forces Day celebrations.

He said he was optimistic – "I'm very positive: you can't restore hope by being sceptical" – but also spoke of his fears for the future.

"We have to make sure there's no reversal of democratic reforms; that there's progress as we move towards an election," he said. "I'm also worried that if there are any incidents of this tension, in 18 months' time, will we be in a position of holding a free and fair election? We must have that election."

By Special correspondent