Sir Ian Blair has been a controversial Commissioner of the Metropolitan Police. Past brushes with controversy include covert tape-recording of calls with the Attorney-General, public criticism of another police force for using a (non-fatal) taser to arrest a terrorist suspect and accusing the Royal Ulster Constabulary of being “an almost completely paramilitary organisation”. In 2005 Sir Ian lobbied for an extension of police powers of detention - a highly political issue - while it was going through Parliament. That was improper given the independence of his role.

Immediately after the killing of Jean Charles de Menezes, Sir Ian's force failed to tell the public the truth; he told his officers not to co-operate with the Independent Police Complaints Commission, blocking access to the investigation scene.

On each occasion I faced pressure to call for Sir Ian's resignation. On each occasion I refused, for it should only be made with the greatest of circumspection and the clearest of causes. However, the prosecution of the Met for killing Mr de Menezes disclosed systemic failings of a different order at the centre of Britain's counter-terrorism capability.

I do not hold Commander Cressida Dick, who supervised the operation, nor the armed officers personally responsible. I recognise that the police were operating under enormous stress. Many showed tremendous courage.

Factfile: revelations from the de Menezes trial

Information about the police killing of Jean Charles de Menezes, on July 22, 2005, that has emerged during the trial

Multimedia

• Pictures: Jean Charles de Menezes

BACKGROUND

• Ian Blair survives no confidence vote

• Timeline: how de Menezes identity emerged

• Come quietly, Sir Ian – you’re banged to rights

• ‘It is my task to ensure that lessons are learnt’

Related Internet Links

• Download full report

But what happened on July 22, 2005? In the early hours, police learnt that Hussein Osman, one of the 21/7 bombers, was living in a block of flats in South London. An undermanned surveillance team was set up and the firearms team took four hours to deploy. That morning Mr de Menezes left his flat in the same block that the police were watching. A series of errors followed.

Surveillance failed to verify his identity clearly - there was no cover for the officer who was indisposed as Mr de Menezes made his way to Stockwell Tube. Mr de Menezes - still a suspected suicide bomber - was allowed to get on and off a bus twice and enter the Underground. Instructions to arrest him were cancelled and then reissued. Once below ground, the police radios did not work properly and the command station issued an ambiguous command to “stop” him.

The trial judge described these multiple errors as a “corporate failing”. They covered resourcing, organisation, communications, training and the tactics on the day. As Commissioner, Sir Ian bears responsibility for such serious and systemic failings. The public must have confidence in Britain's most senior police officer who is entrusted with national security. Sir Ian has lost that trust. His position is no longer tenable. Regrettably, it is time for him to resign.

David Davis is Shadow Home Secretary

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