Leading article: This latest failure will shake faith in Sir Ian Blair

The release of the two suspects arrested in the Forest Gate raid is an admission of dreadful failure on the part of the Metropolitan Police and its head, Sir Ian Blair. Everyone, including the family of Mohammed Abdul Kahar and his brother Abul Koyair, accepts that the police must act on information about potential terrorist acts. But the way they mishandled the case ought to prompt a rapid rethink about tactics if lasting damage is not to be done to police relations with Muslims who now make up at least 10 per cent of the capital's population. That rethink should include asking whether Sir Ian should remain in his job.

It is extraordinary that after the police launched one of the most high-profile anti-terrorist operations the capital has seen since last summer's bombings that having failed to uncover any of the evidence they sought they were then so slow to admit that they had made a mistake and deliver a full, unreserved apology.

Instead, we had the undignified spectacle of the police hanging on like grim death to the suspects until the last possible moment, and issuing only a half-apology of the most defensive kind to "the community" for any disruption they had caused.

The consequences of these actions and omissions are likely to linger, not least because the hefty compensation the two men will seek will keep the story alive for months.

It has all left a very sour taste in the mouths of an entire community that increasingly feels victimised by the authorities. No prizes for guessing what that may mean in turn: radical groups moving in to feed in predatory style on a mounting sense of grievance.

The damage caused by this operation goes beyond the Muslim community. Another unfortunate legacy of the Forest Gate raid is that it will contribute to a more general crisis of public confidence in the basic competence of the Metropolitan Police.

Tony Blair has tried to stem this, rushing out to proclaim that he supported the police action "101 per cent". John Reid said much the same thing.

But the effect of such statements will not last long. The publication of a report by the Independent Police Complaints Commission into the fatal police shooting last July of the Brazilian Jean Charles de Menezes will bring all the worries about lack of leadership at the top of the London police back to the surface. It will not help that Sir Ian may face prosecution over the killing.

So far, Mr Blair has stuck doggedly by his namesake in New Scotland Yard. So has London's mayor, Ken Livingstone. It was not that long ago, after all, that we were being told that Sir Ian was the breath of fresh air London's police force had long needed, with his wide intellect, cultural interests and apparent sensitivity to racial questions. That may all have been the case, but much more crucially he simply appears not to be able to exercise the control over his force that the public has a right to expect.

The Forest Gate affair has brought all the bubbling questions over his leadership style to a head. We have seen the police briefing against each other, not to mention against the family of the two men, information on the shooting of one of the brothers withheld from the public for no known reason, and then, finally, a graceless withdrawal from the scene without due apology. This state of affairs cannot go on if we are not to end up with riots. As Mr Blair thinks hard and fast about restoring public confidence in the police following this latest setback, he must think equally hard about whether Sir Ian is not now more of a liability than a help.