It is one thing for the trade unionists and communists to decry the centralisation of power in the Mbeki administration, and quite another to throw their weight behind Jacob Zuma as the next president of South Africa.

There are many serious democrats who are concerned at the way President Mbeki has concentrated power on the presidency and who would like to see a change in style next time around. But not under Jacob Zuma.

Although Zuma has not yet been found guilty of any crime, there has been enough evidence in the Schabir Shaik case and from his own mouth in the rape trial to show that he is unfit to be president.

He has shown poor judgment in many fields, from his choice of financial adviser to his decision to have a sexual adventure in high-risk circumstances.

He has shown himself unable to manage his own financial affairs, let alone those of the country.

He has been grossly irresponsible in having unprotected sex with an HIV-positive woman, an act the judge described as "inexcusable" and "totally unacceptable".

It was also a dereliction of duty on the part of a man who is supposed to be heading the ANC's Aids awareness campaign and its moral regeneration campaign.

And he has still to face trial on corruption charges, for which his financial adviser has already been found guilty.

Zuma's image internationally is tainted beyond redemption, regardless of the outcome of the upcoming corruption charges. Leading opinion-makers abroad simply cannot understand how a sophisticated country, which is how they have come to perceive South Africa under the Mandela and Mbeki administrations, could begin to regard a man with such a record as a serious contender for the presidency.

They would be appalled if he were elected. Cosatu and the SACP, who purport to care about the level of unemployment and the plight of the poor, must know that the economic consequences of a Zuma presidency would be devastating. Our financial markets would be sent reeling.

We have just had an astonishing $54-billion (R350-billion) of foreign investment flow into the country in the first three months of this year, an all-time record.

That and more would fly out in a day at news that Zuma had been elected president.

Local investors would desperately seek safe havens abroad. Our workers and the poor would be among the worst hit as businesses closed and retrenchments soared.

The rich can always find ways to rescue themselves in a recession. The poor cannot.

Last week, the president of the National Union of Mineworkers, Senzeni Zokwana, dismissed criticism of Zuma's unprotected sex with an HIV-positive woman in an extraordinarily mindless fashion, saying his union - the country's biggest - didn't adhere to the Ten Commandments and didn't need Christians to tell it that adultery was wrong.

"We are not Christians," he said. "We don't listen to the Ten Commandments and we don't have to listen when Christians tell us adultery is wrong. We also don't need Christians to tell us who our leaders should be. We know who our leaders are."

In other words: To hell with morality. Give us our man regardless!

I wonder whether Zokwana gave a moment's thought to how that would sound to the investment community worldwide, who we need so badly if we are to create the jobs the workers he represents need to feed their families.

I wonder, too, whether he and other Zuma supporters have given thought to what economic policies they would introduce should their man attain the presidency.

How do they intend boosting employment if not by increasing economic growth through increased investment? I certainly don't know of any other way. One may fine-tune matters of wealth distribution, but you have to generate the wealth first before you can distribute it.

The point is that one has to come to terms with the realities of today's globalised economic environment, for there is no other.

If the leftwingers do not believe me, let them ask the Chinese and the Vietnamese. And let them look north to Zimbabwe to see the consequences of trying to function outside that global environment.

That said, one must also consider Mbeki's role in this crisis. He must bear some of the blame, for it is his leadership style that has alienated important sectors of the ruling alliance and is now threatening the country with political instability. He has been too imperious in manner and heedless of the complaints and mounting criticism.

It is puzzling what caused him to change on becoming president, for the Thabo Mbeki I came to know during my frequent visits to the exiles in the 1980s was a gregarious man of great warmth and conviviality, as well as being a brilliant political analyst.

On seminal occasions when he met with Afrikaner dissidents abroad he captivated them with his charm and open-mindedness, listening to opposing viewpoints and seeking the consensus way forward.

His powers of persuasion were formidable. And back home, together with Nelson Mandela and Cyril Ramaphosa, he played a key role in bringing about our miraculous national reconciliation.

South Africa has need of those talents now, and it is incumbent upon Mbeki to rediscover them. At the moment he is like a rabbit in the headlights. He must snap out of it. The country cannot afford a lame-duck presidency for the next three years while this succession crisis tears us apart. It needs leadership now.

Mbeki needs to call the alliance leaders together for a crisis summit, listen to their complaints - and heed them.

Let him undertake to give his critics better access in the future, to draw them into the decision-making processes of government and generally treat them with more respect.

Let him seek their co-operation in stabilising the country, and in the process discuss the succession issue with them, trying to find a suitable candidate, other than Zuma, who would be acceptable to them, someone with the talent to heal the rift, the gravitas to command international respect and the ability to lead South Africa into a third dynamic decade of democracy.

Mbeki should also address other issues which have caused dissatisfaction, such as his dilatory handling of HIV/Aids and Zimbabwe.

He could start by removing the Minister of Health, Manto Tshabalala-Msimang, and using the vacancy to reshuffle the cabinet and bring back one of the sidelined ANC heavyweights whom the alliance partners might see as an acceptable alternative to Zuma.

As for Zimbabwe, with Robert Mugabe spitting in Mbeki's face once again with his rejection of a meeting with UN secretary-general Kofi Annan that Mbeki had obviously set up, surely it is time for a more assertive response to this destructive and insulting neighbour.

We have a convenient weapon to hand in our shortage of electricity. This is an appropriate moment for the Mbeki government to announce that we cannot continue supplying electricity to Zimbabwe while we are having power outages at home and babies are dying in hospital incubators.

Then tell Eskom to throw the switches. That would send a message as striking to Mbeki's critics as to the Zimbabweans.

With acknowledgement to Allister Sparks and The Star.