A thick skin, a tin hat and no lust for power: that's all a tycoon needs to go into politics

What works for bosses in the office often fails in high office, writes Heather Tomlinson

Michael Bloom-berg is an unlikely student of Fidel Castro. But the financial information tycoon, turned Mayor-elect of New York, might have appreciated the Cuban leader's comment: "When politicians become businessmen, they generally fail. When businessmen become politicians, very often they are successful ... In general, [politicians] do not have the same firm- ness, the same common- sense as businessmen when [they] do things."

Yet the political graveyard is full of high-flying businessmen who turned their attentions from shareholders to voters. Perhaps Fidel Castro needs more experience of a capitalist state to guide him in his views. He should study the recent history of the UK, where many successful businessmen have crashed and burned in politics, whether the demise was due to scandal or mediocrity.

The most exemplary warning tale comes from Archie Norman, the Conservative MP. When he was elected in 1997, he was a hero of the City of London. In the early 1990s he had taken over as the head of Asda, which was almost on the point of going bust. He performed a miracle and built the company into the success story it is today.

This earned him a special place in the Tory party. Everyone thought he was destined for great things. After all, if he could sort out a backward-looking, demoralised supermarket chain that was on its last legs, surely he could do the same with a political party in a similar state?

But Mr Norman's best qualities in business were not the best qualities in politics. He reformed Asda not only with financial acumen but by cutting bureaucracy and motivating staff. He brought in eccentric ideas like "Tell Archie" suggestion boxes and "black bag" Fridays, where staff had to clear their desks at the end of the week to get rid of useless paperwork. But his modernising style did not go down well with the Tories. "The resistance of the Conservative Party to reform was very surprising," he says. "There's an antipathy to change."

After serving as deputy chairman of the party and as shadow environment spokes- person, he now intends to return to business. And he's got a few words of advice for Mike Bloomberg: "Don't underestimate the difference in the political culture and take the time to listen and understand the differences of what's expected of you. And get a tin hat and a thick skin."

But there have been more suspicious business characters who entered the fray of politics. Robert Maxwell set up his first large business venture, the publishing company Pergamon Press, just after World War II. It was a storming success – at least, it seemed to be – and his hot streak continued when he was elected as a Labour MP in the mid-1960s. But the end of his political career, when he was defeated in the 1970 election, coincided with his first big scandal in the business world. He had been inflating the profits of Pergamon, leading to condemnation from the authorities. The affair put an end to his political ambitions, although not his commercial ones.

The Maxwell legacy haunted another of the business-to-politics tribe, Geoffrey Robinson. The Labour MP for Coventry North West found that the winnings of big business didn't help him in politics – whether it was the cash he loaned to Peter Mandelson or the £200,000 payment that Maxwell allegedly gave him when he was head of Trans-Tec, the company he founded.

The other big stumbling block for a politician who wants to hold on to his business career is conflicts of interest. Lord Sainsbury is still minister for science and innovation, but his appointment caused a furore, as his brief covered genetically modified foods. Lord Sainsbury has a shareholding in his family's supermarket and investments in companies in the GM area, although his commitment to GM foods comes from a strong personal belief in the technology.

Another peer fared worse. Lord Simon suffered many jibes about his large shareholding in BP, where he was once chief executive, during a ministerial role that covered some energy policies. The controversy led to a three-year hiatus in his political career.

And both Lord Simon and Lord Sainsbury had the curse of all significant shareholders who become a minister: the stake must be put into a blind trust, giving them no control or access to their millions.

John Redwood is one of the rare success stories. He was once a director at NM Roths-child and chairman of Norcros, an industrial products company. He also climbed the political ladder during the last Conservative government as a Department of Trade and Industry minister and as Secretary of State for Wales. At first he found a surprising difference in the cultures of business and politics. "It was a shock at the beginning but after a while I liked it," he says. But he adds that the difference in power is substantial. "You don't have anything like the power of hire and fire and giving orders."

When studied, the problems for a power-hungry businessman are clear. A company boss is just that – a boss. In the political world, he or she would be described as a dictator. There's a small matter of pleasing shareholders, but if the profits are rolling in at a company, the boss can expect little trouble.

Perhaps this is why the US system can be more conducive to businessmen. Those who are appointed by the President to executive roles in government – without all the hassle of getting elected – find that their management style is better accommodated, as they can get on and do the job they were appointed to.

Robert Rubin, who was highly successful in Wall Street, working for more than 25 years at Goldman Sachs, also excelled as Treasury Secretary during the Clinton years.

On the other hand, not so many businessmen succeed in electoral politics. Ross Perot, who set up two big technology companies – Electronic Data Systems and Perot Systems – was a seriously considered independent candidate in the 1992 presidential election. After a serious of mishaps, partly due to naivety about the political process, he came third. At least Mr Bloomberg has got himself elected, but his problems have only just begun.