British Prime Minister Gordon Brown fought back against claims he terrified staff with his volcanic temper in book extracts out Sunday which posed a new threat to his general election prospects.

A new book by political journalist Andrew Rawnsley claims Brown grabbed one staff member by the jacket lapels and shouted at him, punched the back of a car seat after receiving bad news and repeatedly swore at advisors.

NONE Brown is also accused of having "turfed a (secretary) out of her chair and (taken) over the keyboard himself" because she was "not typing fast enough", while a seat in his official car was allegedly "flecked with black marks" where he stabbed it with his pen in frustration.

The atmosphere at Downing Street got so bad that the head of the Civil Service, Gus O'Donnell, gave Brown a "pep talk", telling him: "This is no way to get things done," according to extracts in the Observer newspaper.

Downing Street labelled the allegations "malicious" and "totally without foundation", while Brown said any anger was directed at himself.

Meanwhile, the head of the National Bullying Helpline spoke out as the book's allegations became public and said there had been "three or four" contacts with the line from Downing Street staff in recent years.

But Downing Street said the anti-bullying charity had not contacted them about the matter, adding there were "rigorous, well established procedures in place" for staff to deal with concerns over inappropriate treatment.

Colleagues have rallied to support Brown, whose Labour Party is lagging David Cameron's main opposition Conservatives in opinion polls as a general election -- possibly in early May -- looms.

Business Secretary Peter Mandelson, effectively the prime minister's deputy, said the picture painted by Rawnsley was "not one I recognise".

"I don't think he so much bullies people as is very demanding of people, he's demanding of himself," Mandelson told BBC television.

The revelations came the day after Brown launched what party officials called "Operation Fightback" ahead of a general election.

NONE Even though the ballot has yet to be formally called, unofficial electioneering is already under way. The vote must be held by June 3 at the latest.

Brown, who is frequently accused of lacking charisma, has tried to show a more sensitive side in public recently, notably in a primetime television interview last week when he discussed the death of his baby daughter in 2001 and his relationship with wife Sarah.

A Sunday Times/You Gov opinion suggested those efforts had borne fruit, with Labour closing the gap on the Conservatives. It gave the Tories 39 percent support, down one, and Labour 33 percent, up two.

The book extracts told how "during one rage, while in his prime ministerial car, Brown clenched his fist in fury after being told some unwelcome news and then thumped the back of the passenger seat."

It added that the protection officer in the seat "flinched with shock" and "the aide sitting next to Brown... cowered because he feared 'that the prime minister was about to hit him in the face'," The Observer added.

O'Donnell launched his own investigations and felt the need "to calm down frightened duty clerks, badly treated phone operators and other bruised staff," according to the paper.

A spokesman for the Cabinet Office said: "It is categorically not the case that the cabinet secretary asked for an investigation of the PM's treatment of Number 10 staff."

Despite official denials, Rawnsley stood by the contents of his book and told Sky News television it was "not the job of journalists" to advance the interests of one political party.

- AFP