Robert Mugabe has long defied political gravity. But even the most tenacious autocrats eventually land with a bump. It is tempting to think that time is approaching for Zimbabwe’s 84-year-old leader. This Saturday’s elections may not end his rule directly or prevent him taking Zimbabwe further down with him. Mr Mugabe faces the choice between continuing in State House, where he hopes to retain influence over his succession, or humiliation and even jail. For that reason he will use all means at his disposal to ensure the vote count goes his way.

However, the corner he finds himself in is tighter than it has been in previous polls and the political climate more volatile than ever. The old liberation-era rhetoric, blaming Britain for his country’s proliferating woes, has limited appeal for a desperate population.

The defection of Simba Makoni, his former finance minister, who along with the resurgent opposition’s Morgan Tsvangirai is competing for the presidency, has brought splits within the ruling Zanu-PF party into the open. This has thrown Mr Mugabe off balance, raising doubts about the loyalty of election officials as well as the degree of support in traditional rural strongholds.

Nor can last-minute salary increases for civil servants, among other incentives, offer anything but diminishing returns. To fund these, the central bank has been printing money. This will worsen economic conditions in the aftermath of the polls. Inflation is already rising above 100,000 per cent to levels few regimes anywhere have survived for long. If he is to snatch another victory, Mr Mugabe will probably have to rely on force. Scenting blood, the opposition both from within and outside Zanu-PF is unlikely to lie down and take it, raising the risk of a violent contestation of the results.

There is a heavy burden therefore on the shoulders of the Southern African Development Community and the African Union, the only outside organisations permitted to monitor the vote. Controversially, both endorsed Mr Mugabe’s previous election wins. But having stood firm so recently in the face of election fraud in Kenya, and in the AU’s case having played a prominent role in finding a way out of the subsequent crisis, there is pressure to apply the same standards. More­over, to save Zimbabwe from further ruin, whoever wins will have to go cap in hand to foreign donors for a rescue package.

That is unlikely to be forthcoming with Mr Mugabe at the helm. The dilemma is familiar. We can only hope that reason prevails before it is too late.