DAVID BLUNKETT was looking increasingly isolated last night after he was slapped down for his behaviour by Deputy Prime Minister John Prescott.

The Home Secretary publicly accepted he had been "arrogant" to make scathing comments about Cabinet colleagues, as No 10 moved to distance itself from his remarks.

In the first sign that Prime Minister Tony Blair might be losing patience with the Home Secretary, the premier's spokesman said Mr Blunkett's remarks were unfortunate and had been made on a bad day.

Downing Street's move came after Mr Prescott voiced fellow ministers' anger at Mr Blunkett.

The Home Secretary has already apologised to Foreign Secretary Jack Straw, Education Secretary Charles Clarke and Mr Prescott, after his criticisms became public in a biography of him released to news organisations.

Yesterday, Mr Prescott became the first senior minister to criticise Mr Blunkett openly, blaming "an element of personal arrogance" for the comments, with which he "fundamentally disagreed".

Later, a contrite Mr Blunkett made no effort to challenge Mr Prescott's assessment.

A spokesman for the Home Secretary said: "This is perfectly fair comment, which David entirely accepts."

And one North-East Labour MP said last night: "Today has been the first time that MPs are openly talking about Mr Blunkett being fatally damaged."

He felt that even though Parliament would be in recess over Christmas, the story would not be allowed to die by either the media or by Mr Blunkett's former mistress, Kimberly Quinn.

The MP felt that the Home Secretary would probably leave the Government in the new year.

In the biography, by Stephen Pollard, Mr Blunkett brands a range of his Cabinet colleagues soft, weak and prone to panic.

Among his revelations, in interviews conducted before his relationship with married former lover Kimberly Quinn became public, were comments suggesting Mr Prescott was grumpy and was excessively sensitive about his "Two Jags" nickname.

He also accused his predecessor, Mr Straw, of leaving the Home Office in a mess and Chancellor Gordon Brown of being intolerant of other ministers expressing disagreement.

Mr Prescott told BBC Radio 4's Today programme: "I fundamentally disagree with his judgements on his Cabinet colleagues, but to be fair to David, he has apologised publicly and personally to his colleagues and was honest enough to confess to a certain amount of arrogance in his conclusions.

"So the whole issue of judgement on Cabinet colleagues, which the press have seized upon, has come about because of an element of personal arrogance and a very large amount of personal financial gain and book sales for the author."

Asked if he wanted Mr Blunkett to remain in his post, Mr Prescott replied: "That's not a matter for me, but I'm sure that will happen."

Mr Blair's spokesman said Mr Blunkett had "explained the circumstances of his comments and has apologised to his Cabinet colleagues. That's it".

He added: "The Prime Minister has expressed his view of his Cabinet colleagues on many occasions.

"David Blunkett has explained the circumstances in which he made his comments. We all from time to time have bad days and he has apologised."

The spokesman said later: "If you had a bad day and made unfortunate comments, you should recognise that fact. What the Prime Minister agrees with is if you make unfortunate comments, you should apologise for them, and he has done that."

The fall-out from the end of Mr Blunkett's affair has left the Home Secretary fighting for his political future.

On the personal front, he is trying to prove he is the father of Mrs Quinn's son and the child she is expecting in two months' time.

Mr Blunkett is also facing a series of claims that he misused his ministerial position during their relationship.

The most serious allegation is that he fast-tracked a visa application for Mrs Quinn's nanny, Leoncia Casalme.

Former civil servant Sir Alan Budd is investigating the claim, but nobody in Whitehall will say when he is expected to report on his findings.