Matthew Norman: Why are the police allowed to be a law unto themselves?

At this stage of his political career, the only advice worth offering the Prime Minister is to ensure that he has the hemlock with him when he locks the study door in case the trusty Luger jams. But for those of a less fatalistic mindset, a more constructive suggestion would be this. Afore ye go, Gordon, and in pursuance of Tuesday's opaque promise to jettison the ways of New Labour, for God's sake do something about the police.

Of course he wouldn't dream of it. All politicians are petrified by the muscle flexed by the force and its cheerleaders at the Sun whenever the faintest squeak about challenging this cosiest of cartels is heard. Kenneth Clarke wanted to crush the Police Federation, last of the great trade union baronies albeit technically no union at all, had he stayed at the Home Office longer, and he was a political have-a-go-hero if ever there was. But if he had had a go, a panicky John Major would have quickly told him to back off, get behind the cordon sanitaire and... well, let the police handle it themselves.

For all the rumbling row about the backdated pay rise, slavering flattery is the monotone our leaders have exclusively struck since Margaret Thatcher politicised them by loosing them on the striking miners. The British police are the best in the world, they trill without Tom Robinson's engaging sarcasm, and we don't believe all those stories we've heard. Many of us do, though, and further believe that what has so fractured the relationship between the police and the public that they nominally serve is the dearth of scrutiny that stems in turn from the lack of political will to control them on our behalf.

The problem isn't that all officers are workshy, racist, trigger-happy thugs who prefer to spend their days eating doorstep sandwiches in the canteen and doling out speeding fines than catching criminals. Only a hybrid of superannuated Wolfie Smith and right-wing shock jock could take so cretinously simplistic a line. The problem is that we have no clue what they're up to, and no mechanism to find out.

This week alone, further evidence for this comes in triplicate. The High Court is considering the killing of Mark Saunders, the alcoholic barrister shot by Met marksmen in Chelsea after repeatedly firing his own shotgun. Clearly this was nothing on the scale of the de Menezes catastrophe that Sir Ian Blair so brazenly survived to prosecute his internal war with Tarique Ghaffur, whom he has suspended for the only offence for which an officer can ever be punished (highlighting alleged failures by the police, in this case to treat dark-skinned officers as if they were white).

What we don't know about Mr Saunders's death is if it was an error at all – whether he committed "suicide by cop" or whether marksmen overestimated the lethalness of the threat he posed. And the reason we don't know is that the Independent Police Complaints Commission allowed the Met eight days grace, during which those concerned could compare notes and co-ordinate their stories, before starting its enquiry – an almost satirical distortion of evidence-gathering rules, whether or not the High Court finds it in breach of human rights law. In fact, that's cobblers. Had it delayed for eight nanoseconds we still wouldn't know, because that pliant body's raison d'être is not to police the police, but to lend a transparent fig leaf of credibility to their ritual vindication. If the IPPC reckoned that brief suspension was sufficient penalty for the officers who shot dead Harry Stanley in Hackney nine years ago, for holding a carrier bag containing a sawn-off chair leg, it was never odds on to recommend censure, let alone prosecution, for those who killed Mr Saunders.

Meanwhile, a report by the ISC committee of peers and MPs into communication failures between West Yorkshire police and MI5 before the London bombings of 7 July 2005 has been abandoned "for legal reasons", whatever they might be. The PM has read the document, which apparently implies that the bombings may have been avoidable, but prefers to keep it to himself, possibly for fear of distressing any poor police darlings already traumatised by a jury's scepticism regarding the guilt of those charged with conspiring to blow up planes with bombs made from formula baby milk and contact lens cleaner.

The humiliating failure of yet another major terrorist prosecution is something else for which no officer will ever be held accountable, just as none will be punished for the wrongful conviction of Barry George or any of the perpetual miscarriages that erode residual faith in the justice system. In the case of the airline bomb plot, it might very well be that Scotland Yard played a blinder but was undermined by factors beyond its control. But in the absence of proper scrutiny, as in the case of Mr Saunders, how does anyone form a judgement?

By now (by paragraph two, in fact) some sensitive flower from the Association of Chief Police Officers, and some queeny Police Federation hysteric, will be composing the outraged response that traditionally follows a piece of this kind, drawing attention to the selfless devotion of those they represent to protecting us from harm. Yet no one sane disputes the gratitude owed to those whose job it is to keep us safe, and patting officers on the head for doing what they're paid to do is a massively tiresome distraction from the futile business of trying to hold them accountable when they don't do what we pay them to do, or do what we pay them not to do.

I may be wrong about this, as I am about most things, but from the osmotic evidence that tends to be the most reliable guide to something as nebulous as national mood, I sense a burgeoning appetite for the taming of the police; that whether it is the comparatively trivial (that estimated 30 per cent of officers on the sick due to "stress"), the farcical (the continued presence of that posturing buffoon Ian Blair), the plain disgraceful (shooters threatening to hang up their holsters if a colleague is punished for a fatal error), or the cowardly (officers hiding beneath the skirts of that wretched IPPC), a huge chunk of the populace has had it with the police being a law unto themselves.

If so, the verity that going to war with the law is political suicide is no longer a verity but a misreading, and a clear populist opening exists for a politician with the stomach to clean out those Augean stables without puking too violently at the stench of self-protective secrecy. But that would take courage, and when it comes to that precious commodity, Gordon's pen, as we all know, is sharper than his sword.