The BBC was accused last night of caving in to pressure from the New Labour high command to rein in the combative interviewer. Humphrys claimed he had been "stitched up" after his "light-hearted" speech to public relations executives came to light at the weekend in The Times, which accused him of implying that all ministers are liars.
It has since emerged that the only person to request a videotape of the event was Tim Allan, who was deputy to Alastair Campbell, the former Downing Street communications director. He is believed to have passed it to The Times.
Supporters of Humphrys consider Mr Allan's move to be part of a revenge attack on the BBC following the Hutton inquiry into the death of the government weapons expert David Kelly, the source of a BBC report that No 10 had "sexed up" a dossier on Iraq's weapons.
Mr Campbell demanded the scalps of BBC bosses and three central figures involved - the chairman Gavyn Davies; the director general, Greg Dyke; and the reporter Andrew Gilligan. All resigned.
In a report commissioned by Michael Grade, the current BBC chairman, Mark Byford, the deputy director general, concluded that although Humphrys was speaking in a personal capacity his comments could be used to question his own impartiality and that of the BBC.
According to the report, Humphrys, who has defended his remarks about senior Labour politicians as "light-hearted", has accepted that some of the views he expressed in a speech to the Communication Directors' Forum in June were "injudicious".
The presenter of Radio 4's Today programme has given an undertaking that when speaking at outside events in future, he will fulfil the requirements expected of a leading BBC presenter.
Rod Liddle, a former editor of the daily news programme, said: "The BBC after Hutton seems to have lost its spine. It has no intellectual grip on what constitutes impartiality, objectivity and subjectivity. It doesn't understand that we know that presenters and journalists within the BBC have views and that if they have given a speech about them, it's a form of transparency.
"If what John said demonstrates anything, it demonstrates utter impartiality. He's the most impartial journalist I've ever come across ... He's sceptical of all politicians."
Mr Liddle added: "It should be noted that the newspaper which published this biased and incorrect report of what John Humphrys said is part of a New Labour cabal which has always hated John Humphrys. That very newspaper, The Times, has since said the comments are of no consequence whatsoever."
Senior Tories and Liberal Democrats were disappointed at the BBC's ruling. David Davis, the shadow Home Secretary, said: "It is outrageous that Alastair Campbell's former henchman is seeking to undermine the reputation of one of the country's foremost journalists. It is the job of the governors not to give in to these bullying tactics."
Lord Tebbit, the former Tory chairman, said: "The BBC is more interested in its relationship with the Labour Party and the Government than with presenting facts fairly and honestly."
Sir Menzies Campbell, the Liberal Democrats' foreign affairs spokesman, said the BBC should have been more robust. "It really is time this Government grew up. John Humphrys gives us all a hard time. The Government should be big enough to take it on the chin - and not to indulge in stings like this."
The offending remarks
On Andrew Gilligan's report on the "sexed-up" dossier
"All of which, with one small emendation [sic] turned out to be true... the fact is we got it right. If we were not prepared to take on a very, very powerful government, there would be no point in the BBC existing."
On Tony Blair
"We have not been the closest of friends over the last four or five years - indeed we've scarcely spoken to each other."
On Peter Mandelson
"Now there is a man they, I think probably all, detest. I said to someone once: 'Why do you all take an instant dislike to Mandelson?'"
On Gordon Brown
"He is quite easily the most boring political interviewee I have ever had in my whole bloody life."
On John Prescott
"All you've got to do is say John Prescott and people laugh... I'm sure he makes sense but it's just that you can't understand a bloody word he says. "
"There are those who do not lie at all, ever, and they don't get into government. The whips won't go near you with a barge pole - well they will but only to push you into the lake. The second lot are those who lie but really don't like it. And the third lot couldn't give a bugger whether they lie or not. And there are some of those."
Victims at the corporation
Alastair Campbell called for the scalps of four senior BBC figures on the day the Hutton report was published. Only John Humphrys remains in the same post.
The BBC chairman resigned on the day that Lord Hutton published his damning indictment of the way the BBC handled the row with No 10 over the journalist Andrew Gilligan's report on the Today programme claiming that the Government had "sexed up" its Iraq dossier.
One resignation was not sufficient to quell the furore that engulfed the BBC post-Hutton and much to the chagrin of staff, the director general handed in his notice under pressure from the governors.
The BBC news chief, strongly criticised by Lord Hutton, was moved sideways to oversee the BBC's World Service and its global news division in a management reshuffle ordered by the incoming director general, Mark Thompson.
The veteran Today presenter seemed secure in his job, until comments he made in an after-dinner speech were leaked to the press, with the finger of suspicion pointed at Tim Allan, a former aide to Mr Campbell.
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