By Mary Ann Sieghart
BBC Radio 4 Profile
Sir Gus is known for his people and communication skills
His nickname is 'God' - after his initials.
But Sir Gus O'Donnell, the country's top civil servant and Gordon Brown's cabinet secretary, could not be more different from the archetypal Sir Humphrey caricature.
Last week, he was embroiled in the latest allegations over bullying at Number Ten.
The journalist Andrew Rawnsley claims in a new book that the prime minister's behaviour towards his staff was so bad that O'Donnell was forced to give him a pep talk.
On Wednesday, the cabinet secretary appeared before the Justice select committee to answer questions about it. He said: "I've never talked to the prime minister in relation to bullying Number Ten staff, but of course I've talked to the prime minister about how to get the best out of his civil servants."
It may sound like a categorical denial, but O'Donnell chose his words with great care.
It is a skill that has stood him in good stead, according to Financial Times columnist and veteran Whitehall-watcher Sue Cameron.
"It's his people skills that are so good, but I think he also has a tremendous flair for how he presents things, for avoiding confrontation, for finding a different way, for calming things down. In another person you'd almost say he's as slippery as an eel."
This is a man who has served three prime ministers, but who did not come via the traditional public school route. Gus O'Donnell, the youngest of five children, is a south Londoner who went to a Catholic grammar school in Battersea.
At school, O'Donnell, now 57, was more interested in football than maths. According to his maths teacher, Pat Howes, he had to work hard to win his place at Warwick University to read Maths and Economics.
The then Chancellor Nigel Lawson wanted Gus O'Donnell on his team
O'Donnell and his brothers were the first in his family to go to university.
From Warwick he went to Nuffield College, Oxford to do a masters degree, before lecturing for four years at Glasgow University. He joined the Treasury as an economist in 1979.
Within ten years, his ability had been spotted by the then Chancellor, Nigel Lawson, who offered him the job of Principal Private Secretary. O'Donnell declined, as he had just become a father and did not want to work frequent late nights.
So Lawson said: "'How about becoming my press secretary instead?', because I wanted him as part of my personal team, and he said 'yes, I'd love to do that'."
Lawson admired his intellect and understanding of economics, not something you can bank on in press secretaries.
John Major, Lawson's successor as chancellor, inherited O'Donnell and liked him so much that he took him to Downing Street when he became prime minister. Both were state school boys from south London and symbolised the new meritocracy that Major so favoured.
At least to start with, O'Donnell was popular with the Westminster lobby. He was more approachable than his predecessor, the much more confrontational Bernard Ingham.
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On foreign trips, O'Donnell mingled - and drank - with the journalists.
He also shared Major's passion for cricket. Sue Cameron recalls: "One of the first things they did when they got abroad was to set up a special operations room so intelligence could be brought to the prime minister.
"And one of the things Gus and John Major used it for," she laughs, "was to make sure they had the cricket scores. And football is one of the major topics of conversation with Gordon Brown."
But in the autumn of 1992, after Black Wednesday when the pound was ejected from the European Exchange Rate Mechanism, nothing went right for John Major's government. Some Tory MPs blamed the messenger, Gus O'Donnell.
Relations with the press soured, too. George Jones was then Political Editor of the Daily Telegraph and remembers that "the Lobby collectively turned on Gus as he was the interface for them with John Major. As they turned onto John Major, it ended in tears as these relations do."
After four years at Number Ten, O'Donnell returned to the Treasury, probably with some relief.
He soon became the UK's executive director to both the International Monetary Fund and the World Bank, based in Washington.
Patricia Hewitt, the former Labour Health Secretary, was doing research there on Bill Clinton's health reforms.
"He was bright and exceptionally good with people," she remembers. "When I became Economic Secretary to the Treasury a few months later - the Treasury has a reputation for arrogance - I realised that Gus is unusual as he's both bright and he's got people skills."
In 2002, O'Donnell was made Permanent Secretary at the Treasury, working alongside Gordon Brown as Chancellor. Brown, who does not easily like people whose background smacks of privilege, will have approved of O'Donnell's state education, man-of-the-people manner, and glottal stops.
And O'Donnell will not have shouted back at the then Chancellor. Nigel Lawson thinks that: "If he has a weakness, it's that he's a little bit deferential, perhaps a little bit too deferential. He does not like confrontations at all."
Tony Blair stole him away to Number Ten as Cabinet Secretary, the top job in the Civil Service, in 2002. He promptly signed up to New Labour's modernising agenda, and, for example, insisted on moving from his wood-panelled office into an open-plan one at least one day a week.
When Gordon Brown took over from Blair, O'Donnell remained as Cabinet Secretary.
Some of his predecessors in that role have been frustrated at being kept out of the loop by their prime minister, in favour of political advisers.
But according to Sue Cameron, "Gus has hung on in there and maintained and strengthened the civil service's influence. He does have this amazing ability to get on with everybody. He is good with people and he's good with very different people.
"He worked with John Major, and for Tony Blair and Gordon Brown. Three more different men it would be quite hard to imagine."
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