The de Menezes killing happened on Sir Ian Blair’s watch, yet the worst consequence for the Metropolitan Police was a conviction for breach of health and safety regulations, as if the offence was of no more import than leaving packing cases blocking a fire escape.

This, despite the fact that Blair breached his statutory duty to refer the incident to the Independent Police Complaints Commission.

As to the accusations that he favoured his white mates for promotion over better-qualified black and Asian officers, it’s not my job to take sides in Scotland Yard office politics.

On the basis of what I’ve read, I’m inclined to give him the benefit of the doubt. But ultimately the issue will be decided before the relevant industrial tribunals, as is proper in such cases.

Then again, it does seem that he bunged another pal a lucrative public money PR contract, which while not necessarily improper, is bloody silly thing to do when you know that the political heat is on. That provided just the pretext Boris Johnson needed to administer the sack.

But Blair had plus points, too. The most important of these - in the wake of the 1999 Macpherson report, which blasted the Met’s ‘institutional racism’ - is an apparently sincere commitment to what is known as anti-racist policing

Many on the left have got difficulty with the phrase ‘anti-racist policing’, so let’s put it another way. Blair at least made it plain that open racism would no longer be tolerated in London’s police force. That was something that needed to be done.

As it goes, the Met is the closest thing I have got to a family business. My grandad and two uncles were all plods. The degree of overt racial prejudice they displayed was shocking. One of them - a licensed firearms officer, now thankfully retired - routinely referred to black people as ‘sooties’. Macpherson didn’t hear the half of it.

As a poster child progressive copper, Blair is said to have made inroads into the Met’s so-called canteen culture. Good. Yet his reward was to get himself branded ‘politically correct’ in the Daily Mail. That is one of the worst things that can happen to anybody in public life.

Another thing in Blair’s favour is that he succeeded in cutting crime. This or that statistic may be subject to quibbling, but all point in the same direction, and that is downwards. Surely that’s the final yardstick of what policing is all about?

In the end, all of the above considerations are irrelevant. Blair was too close to New Labour, which meant that in the new scheme of things at City Hall, he had to go.

Ken Livingstone - writing in the Guardian today - holds up Blair as a ‘hard working and impressive public servant’ who fell victim of a sustained hard right witchhunt, and there is enough truth in the suggestion to merit a partial defence in the face of a nasty and reactionary media onslaught that is preparing the way for a BoJo placeman.

As ever, the Daily Mail has been leading the way on this one. Melanie Phillips is particularly splenetic this morning. But last time I checked, Paul Dacre wasn’t actually constitutionally entitled to decide on senior police appointments.

Let’s just say Sir Ian did himself no favours along the way. All the Tories had to do was give him enough rope.