Comment: Met chief must pay the price

So, he has no intention of taking responsibility for the catalogue of delays, failures in communication, cross-purposes and incompetence during the Met operation that led to the death of an innocent man and which the trial exposed.

The number of grave police failures during that operation was 19 - and the Met admitted none of them.

In these circumstances, the public will hardly be satisfied by Sir Ian's promise that "lessons will be learned" from the affair, nor by the imposition of a fine of £175,000, which will, like the costs of the case, be paid for out of the public purse.

They are unlikely to be convinced by the Mayor's argument that it was not the Met so much as the British legal system that was found wanting in the trial. Someone must be held to account for the Met's failures. It ought to be its Commissioner.

No one disputes that the police were under extraordinary pressure the day after the failed bombings of 21/7. There were suicide bombers at large in London and the public expected the police to find them.

In such operations, it may be necessary for police to be ruthless in dealing with a suspected bomber, including recourse to lethal force - and it is important, as the Mayor also points out, that the police should not become unduly cautious now in dealing with future terrorist threats.

But a willingness to use force is one thing, serial incompetence and inept communication are quite another. Where an operation of such seriousness is found wanting in so many respects, the responsibility has to go right to the top, to the man who is ultimately in charge. That is the principle of accountability. Politicians go when major errors are found in their department; the same should go for other public figures.

Granted, if Sir Ian had a different record to date, the pressure for him to go now would be less compelling. His predecessor, John Stevens, would probably have been able to weather a crisis like this, precisely because he enjoyed the confidence of the public and the support of his colleagues.

Sir Ian, who is saddled with the reputation of a political New Labour appointment, plainly does not, even though he has a good record in his main job, leading the fight against crime in London.

If he does not go now, this affair will remain to haunt him - when the Independent Police Complaints Commission report into the shooting is published next week and certainly if he loses the Metropolitan Police Authority's vote of confidence in him. For Sir Ian to hang onto office in these circumstances is neither honourable nor sensible. He should go now.