Read the police letters on the counter-terrorism legislation

Sir Ian Blair, the beleaguered Metropolitan police commissioner, is said to have fallen out with Jacqui Smith, the home secretary, after he appeared to backtrack in his support for plans to jail terror suspects for 42 days without charge.

Whitehall officials claim that Blair, for years Labour’s favourite policeman, has privately lost the support of Smith following a disagreement over the Met’s “equivocal” backing for the controversial 42-day law. One said: “Jacqui Smith absolutely hates him.”

Although the Home Office and Scotland Yard formally deny there has been a row, the two are said to have disagreed over a letter sent to Smith last month by Bob Quick, the Met’s assistant commissioner. Quick was “clarifying” the Met’s formal position on the new counter-terrorism bill.

The bill is facing likely defeat in the Commons next month, with at least 50 Labour MPs preparing to vote against it.

In a bid to sway their views, Smith has repeatedly cited Blair and Quick as supporters of the new law, saying that if the police think it is necessary then the move is justifiable.

However, a private letter to Smith, signed by Quick and approved by Blair, fails to give clear-cut support.

One senior official says the letter falls far short of giving her the full backing she wanted – and does not even mention the phrase “42 days”.

“Bob Quick’s letter was very equivocal. In essence, it was saying that the Met could see a possible time when 42 days might be of use,” said the official.

“He was suggesting that at some stage in the future it might be appropriate. But this was a long way from suggesting the Met was fully behind it.”

Smith and Gordon Brown have repeatedly argued that the proposals were necessary to give police extra time to question suspects in highly complex terrorism cases.

While officially Blair has appeared to toe the government line on 42 days, he has been forced to accommodate growing discontent within the Met’s own senior ranks about the plans.

He startled Home Office officials two weeks ago when he told MPs: “We have never put forward a case that there is evidence for an extension of the length of precharge detention.”

Some senior officers in the Met are far from convinced that 42 days is necessary. Tarique Ghaffur, one of Blair’s most senior deputies, recently cast doubt on the need for such a long detention period.

Ghaffur told friends that he opposed the new limit because it could harm relations with the Muslim community.

Officials say the alleged dispute with Smith has made Blair even more vulnerable following last weekend’s election of Tory Boris Johnson as London mayor.

Johnson has said publicly that he will work with Blair – only because he does not have the power to sack him. That remains the prerogative of the home secretary.

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