The head of one of Britain's largest anti-bullying charities revealed yesterday that its helpline had taken calls from Downing Street staff complaining about the atmosphere at work.
Christine Pratt, of the National Bullying Helpline, said she had "seen red" when she heard ministers deny that there was a problem with the workplace culture inside No 10, after a new book catalogued a series of incidents in which Gordon Brown is alleged to have lost his temper and shouted at staff.
The book, by the political commentator Andrew Rawnsley, claimed there had been so many complaints that the Cabinet Secretary Sir Gus O'Donnell warned the Prime Minister about the treatment of staff.
That story was officially denied by the Cabinet Office. "It is completely untrue to say that the Cabinet Secretary ever gave the PM a verbal warning about his behaviour," a spokeswoman said. The Prime Minister's spokesman said of the book: "These malicious allegations are totally without foundation and have never been put to No 10."
But Rawnsley said he was "100 per cent sure", based on first-hand evidence, that Sir Gus had looked into Mr Brown's behaviour and personally warned him to calm down.
Mrs Pratt, who founded the helpline after being a workplace victim herself, accused ministers of "going into denial". She said: "I have personally taken a call from staff in the Prime Minister's office, staff who believe they are working in a bullying culture and that it has caused them some stress. We would have hoped Gordon Brown would lead by example. If an employer receives complaints they should investigate.
"I am not saying Gordon Brown is a bully. But I am appalled at the outright denial that is going on without due process being followed."
Mrs Pratt said there had been "three or four" contacts with the helpline from Downing Street staff in recent years. Her remarks were seized on by the Tories, whose spokesman said: "This development suggests that there could be a cover-up at the heart of government over the Prime Minister's behaviour."
The shadow Foreign Secretary, William Hague, said the allegations in Rawnsley's book suggested that Mr Brown is not "cut out" for the highest office. "I don't think he has ever shown that he can lead a happy team and a successful team, and maybe if there's any truth in these allegations, I think that is one of the reasons he has struggled," Mr Hague told Sky News.
Earlier, the Business Secretary, Lord Mandelson, defended the Prime Minister on BBC 1's Andrew Marr Show. "I don't think he so much bullies people as he is very demanding. He is demanding of himself; he is demanding of people around him; he knows what he wants to do; he does not like taking no for an answer from anyone; he will go on and on until he has got a policy and an idea in the best possible form which he can then roll out," he said.
"There is a degree of impatience about the man but what would you like – some sort of shrinking violet at the helm of the Government when we are going through such stormy waters?"
The Home Secretary Alan Johnson said he had known Mr Brown for 17 years and had "never" heard him swear or raise his voice. "What amazes me, given Gordon's central position as Chancellor and then Prime Minister for so many years in so many difficult, fraught, pressurised situations, is how calm and how softly spoken he remains through that," he told BBC 1's Politics Show.
*When a secretary was "not typing fast enough", Mr Brown "turfed the stunned girl out of her chair and took over the keyboard".
*Informed by deputy chief of staff Gavin Kelly of the loss of computer discs with the personal data of 20 million people, Mr Brown "leapt across the room" and "grabbing a startled Kelly by the collar ... snarled 'they are out to get me'."
*Long-serving senior adviser Stewart Wood was "roughly shoved aside" and sworn at after arranging a lunchtime reception for EU ambassadors. "I don't want to meet these fucking people," the PM said.
*Given another piece of unwelcome news in the back of his car, the PM "reacted by swinging back an arm and clenching his fist" causing an aide to cower, before he "crashed his fist into the ... seat in front".
*When he found out a paper was to report that his party conference speech borrowed phrases from US politicians, he screamed at American speechwriter Bob Shrum: "how could you fucking do this to me?"
*Lord Mandelson: "I don't think he so much bullies people as he is very demanding of people, he's demanding of himself. He does not like taking no for an answer."
*Alan Johnson: Everyone's got a bit of a temper. Given Gordon's central position as Chancellor and then Prime Minister... for so many years in so many difficult situations, [what's surprising] is how calm and how softly spoken he remains through that."
*Harriet Harman: "He won't be a shrinking violet until the economy is fully in recovery and nobody is unemployed. He passionately cares about things, but that's a good thing."
n Jacqui Smith: "He's never shouted and screamed at me and I haven't heard others saying that... you can see sometimes when you look at him that he sort of looks slightly glowering."