By Sean Curran BBC political correspondent, for Radio 4's World at One

Harold Macmillan thought his government might last six weeks

Instead members of the Cabinet were called in, one by one, to see the Conservative elder statesman, Lord Salisbury, who asked them to choose between Rab Butler, the leader of the Commons and the then chancellor, Harold Macmillan.

Few expected Macmillan to succeed. Suez had damaged Britain's international standing. And there was a feeling that voters were tired of the Tories - less than two years after a general election.

When Harold Macmillan went to see the Queen in January 1957 he warned her that his government might only last six weeks.

'Super Mac'

Within three years he'd been dubbed "Super Mac".

The nickname was given to him by a cartoonist and was meant to be ironic. But, as Tony Blair pointed out earlier this week, British politics and irony do not always mix and before too long the nickname was being used in earnest.

Macmillan went on to lead his party to victory - and an increased Commons majority - at the next election. The perfect model, you might think, for any other chancellor looking to take over the top job following unpopular military action in the Middle East.

The chancellor is the frontrunner to succeed Tony Blair

Gordon Brown is understood to have studied previous transitions as part of his efforts to avoid the mistakes of the past.

The journalist and historian Francis Beckett is the editor of a series of 20 biographies of 20th Century British prime ministers.

He wrote the volume on Harold Macmillan and he is currently working on a book about Gordon Brown.

Last year for the BBC History Magazine, Francis Beckett judged the prime ministers on two criteria: First did they have a clear idea of how they wanted to change the country (and how far did they succeed?). And second, how effective were they at managing change?

Unhappy history

Harold Macmillan was judged to be on a par with Winston Churchill and outscored Herbert Asquith, David Lloyd George, Harold Wilson and Tony Blair to name but a few.

Francis Beckett thinks that if Gordon Brown wants to make it into the upper reaches of any future prime ministerial league, he will need to be like Macmillan.

Gordon Brown's living, waking nightmare [is that he will be] tacked on to the end of somebody's else period of office who is only ever really remembered for the fact that he was prime minister Francis Beckett Historian

Political crown princes have an unhappy history. Anthony Eden waited years to take over from Churchill but was prime minister for just eighteen months.

Francis Beckett believes that "Gordon Brown's living, waking nightmare" is that he will be like James Callaghan or Alec Douglas Home, a prime minister "tacked on to the end of somebody's else period of office who is only ever really remembered for the fact that he was prime minister."

Beckett argues that Macmillan was the bridge that allowed Britain to pass from Edwardian England to Thatcher's Britain and that Gordon Brown will need to take the country from Thatcher's Britain into a kinder political world.

At first glance Harold Macmillan and Gordon Brown do not have much in common.

Edwardian gentleman

A product of the age of deference and a veteran of the First World War, Harold Macmillan, with his background of Eton, Oxford and the Guards cultivated the style and image of an Edwardian gentleman.

Gordon Brown is famously "a son of the manse" who has been too busy burning the midnight oil at the Treasury to spend much time cultivating or polishing his image.

There are however some similarities. Both have strong links to Scotland. Harold Macmillan, descended from a crofter, went to great lengths to emphasise his Highland connections.

And both men suffered a personal trauma in their youth. Serving in the trenches during the Great War, Harold Macmillan was wounded and spent some time trapped in "no man's land", reading Aeschylus as he waited to be rescued.

The Suez crisis ended Anthony Eden's prime ministerial career

His injuries caused him pain for the rest of his life and left him with the shuffling gait that was to be lampooned by satirists in the 1960s.

Macmillan's experiences as a soldier set him apart and he was often rather dismissive of people who had not fought in the war.

The 16-year-old Gordon Brown was injured in a rugby accident and lost the sight in one eye. He had to spend a lot of time on his own in the dark following eye surgery.

The chancellor recently told a Fabian Society conference that he spent most of that time listening to Radio One.

'Never had it so good'

And of course both Gordon Brown and Harold Macmillan have been chancellor of the exchequer. The economy was Macmillan's main political interest throughout the whole of his career but he was only chancellor for a short while.

Gordon Brown's biographer, William Keegan, the economics commentator for the Observer, believes that the present chancellor is not that interested in economics but has used his long run in the Treasury to influence much of domestic politics.

There is one economic connection. William Keegan says both men subscribe to the "never had it so good" school of economics.

Gordon Brown isn't Harold Macmillan in the Suez sense, in the Iraq war sense really at all, because private indications are that he didn't really believe in the Iraq war Professor Peter Hennessy

Harold Wilson accused Harold Macmillan of being "first in and first out" of the Suez crisis that ended Anthony Eden's prime ministerial career.

The journalist and historian, Professor Peter Hennessy, whose latest book, "Having It So Good" is a history of Britain in the 1950s, believes: "Gordon Brown isn't Harold Macmillan in the Suez sense, in the Iraq war sense really at all, because private indications are that he didn't really believe in the Iraq war".

And he says the description of "first in, first out", can't be applied to Gordon Brown.

"What does fit" according to Professor Hennessy, is the situation where a chancellor takes over from a prime minister "who, in the case of Anthony Eden was thoroughly discredited and ill, and was going out on the back of the ruins of this crisis.

"Tony Blair is some distance from the Iraq war but not its crisis-laden legacy."

'Country house Cabinet'

What about the day to day running of government? How much laughter will there be round the Cabinet table when Gordon Brown is in charge?

There was, according to, Lord Hailsham, "an element of the dining club or the country house party" about Macmillan's conduct of Cabinet meetings. Peter Hennessy doesn't think Cabinet meetings have been "fun" since 1963, when Harold Macmillan left office.

And he makes another point about working style: "Macmillan was very good at working with civil servants quite widely... but Gordon Brown prefers to work with a small number of people he knows, which is how he operates in the Treasury.

"Quite a high few of them are career civil servants, they are not all special advisers (political appointees) by any means but the trouble is as prime minister you cannot operate just through the people you know."

It is always risky to draw direct lessons or parallels from history. As Professor Peter Hennessy says, "no parallels are exact or fit properly, but they're tremendous fun nonetheless".

The World at One is broadcast weekdays on BBC Radio 4.