Robert Mugabe in all his 84 years has not until now been known for comedic flair. But what else other than a keen sense of humour could explain his claim - made via his Zanu-PF allies - that the Opposition had cheated in Zimbabwe's election, hence the need for a recount in 16 constituencies? With a wit like that, the President could spend his overdue retirement wowing crowds at seaside and spa towns across Britain with lines like “How do you blow up the world's biggest balloon? With 100,000 per cent inflation” or “There is supposed to be an obesity crisis, isn't there? Someone had to have the courage to stop his people overeating.” Ken Dodd must be quaking at the competition.

There is, alas, no evidence that Mr Mugabe intends to abandon Harare for Harrogate. He is instead preparing for a second round in the presidential election where he will use every possible trick to have himself declared the victor. This is obvious to virtually all of Africa (and beyond) except one individual, Thabo Mbeki, South Africa's President and architect of a “quiet diplomacy” approach towards his neighbour.

Before meeting Gordon Brown this weekend, surreally opting to be in Hertfordshire at an hour when the southern half of his continent is in meltdown, Mr Mbeki said that the present situation in Zimbabwe is “manageable” and this is “not the time to interfere”.

It is difficult to decide which of those two statements is the more fantastic. If today's circumstances in Zimbabwe - in which an election result has been shamelessly held back until the incumbent figures out what the numbers released should be, real GDP has shrunk by half since 2000, production of maize has fallen by 90 per cent from then, inducing starvation, and unemployment is at an effective rate of 80 per cent - are manageable, one struggles to divine what might be the kind of conditions that Mr Mbeki would deem “not very manageable”. And if this is “not the time to interfere”, precisely what scale of political malpractice and economic anarchy would prompt him to back “limited intervention”? In his own way, Mr Mbeki could rival Mr Mugabe when it comes to Tommy Cooper territory.

The South African President has, unfortunately, form on this question. When Mr Mugabe swiped the last presidential contest in 2002, Mr Mbeki said his win was valid. In advance of the 2005 parliamentary poll in Zimbabwe, marked by massive intimidation and a media muzzling of the Movement for Democratic Change, Mr Mbeki announced that “I have no reason to think that anything will happen... that anybody in Zimbabwe will act in a way that will militate against the elections being free and fair.” Despite the fact that the ballot conducted was more rigged than a 150ft clipper ship, Mr Mbeki's chosen observers published an account in which they “congratulated the people of Zimbabwe for holding a peaceful, credible and well-managed election which reflects the will of the people”. Not long afterwards, Mr Mbeki used a television interview to blame “divisions within the MDC” as the main reason why he had, sadly, been unable to broker a settlement.

This is not “quiet diplomacy”, it is naked appeasement. It also makes the South African President the second-most responsible man for the catastrophe that is modern Zimbabwe.

The only reason why Mr Mugabe did not declare himself re-elected instantly is because election monitors from South Africa who were independent of Mr Mbeki insisted that the results be posted locally. This enabled a reasonably accurate assessment to be made of the numbers which would be difficult for the Zimbabwean Election Commission to overturn. This information should have been sufficient for Mr Mbeki to have stated that, at a minimum, Morgan Tsvangirai had outscored Mr Mugabe in the initial election and that more external observers should be in a position to scrutinise the final run-off closely. If he had done this a week ago, Mr Mugabe may well already have been heading out of his office.

Britain has been exercising its own version of “quiet diplomacy” on Mr Mbeki. Mr Brown seems to have stuck with this softly, softly strategy. The theory is that if we keep the volume down in public and persuade in private, Mr Mbeki in turn will convince Comrade Bob to be less beastly to his opponents and his population and take off for a villa somewhere. Yet this low-key approach has yielded almost nothing, and probably never will.

This is the moment to be ready to adopt the only course of action that might humiliate Mr Mbeki into finally taking decisive measures. Britain should overtly open a direct dialogue about Zimbabwe with Jacob Zuma, the South African President's deputy, the man who recently defeated him for control over the ANC and hence his heir apparent. Mr Zuma is not the most appealing of men, with accusations of corruption as well as sexual impropriety surrounding him, but on the Zimbabwe matter he is a comparative pragmatist and does not seem to believe that Mr Mugabe is owed any favours for his stance in the 1970s.

Mr Zuma would relish the chance to take centre stage and emerge as Zimbabwe's saviour and a regional statesman, 12 months before he prepares to assume the presidency. That this would profoundly embarrass Mr Mbeki, whom he loathes, would be an added bonus. It would also allow him to rebuild personal links with his own business community which has been desperately lobbying for something to be done about the economic damage being done to South Africa by Zimbabwe's collapse.

Zimbabwe and Africa cannot afford Mr Mugabe to be in office a year hence. If he is, then the exodus of people, perhaps two million more, will reduce what little is left of the country to total destitution. The task of salvaging its economy would be all but impossible. Zimbabwe's very last hope depends upon a transfer of power in the next few weeks. The idea that the MDC has stolen the parliamentary election might be side-splittingly funny. The notion of Mr Mugabe carrying on, by contrast, is no joke.

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