John Rentoul: The police are a law unto themselves

Raiding four addresses on the basis of 'inference' and 'intelligence' alone, the Met has overstepped its mark

David Ruffley, the Conservative police spokesman, last week published a plan to "save one million hours of police time". How timely. Unfortunately, he missed out one important proposal: when considering investigations that involve Members of Parliament, the police should be required to make very sure that they know what they are doing.

That would have saved about 25,000 hours of police time in the cash-for-honours investigation that ended a year ago. And it would have saved the many hours of the 20 police officers involved in arresting Damian Green, the Tory immigration spokesman, and searching his homes and offices last week.

David Cameron used the word "extraordinary" to describe the police action. How right he is. The arrest of Green piles improbability upon arrogance upon constitutional outrage. The use of the fuzzy common law offence of conspiring, aiding or procuring "misconduct in a public office". The deployment of counter-terrorist officers. The use of the power of arrest ("If they wanted to talk to Damian Green, why not pick up the telephone and ask to talk to him?" asked the Tory leader). The searching of offices in the House of Commons, the legally privileged precincts of our elected representatives. "Heavy-handed", another of Cameron's phrases, hardly covers it.

Yet what did Cameron say when the Metropolitan Police came knocking for Ruth Turner, Tony Blair's adviser, at 6.10 in the morning? Nothing. What did he say before that when Sir Ian Blair, the Met Commissioner, decided, on the basis of no more than a press release put out by a Scottish National Party MP, to investigate the allegation that peerages were sold? Again, nothing.

Hypocrisy is nothing new, of course, but surely this is one issue that is above party politics. Indeed, one of the encouraging features of the reaction to Green's arrest is the unease of so many on the Labour side about the police overreaching themselves. Many Labour ministers, at least, seem to recognise that the conduct of this police inquiry is bad for democracy.

If someone asks how the police decide when to investigate an allegation, they cannot now be dismissed as partisans for the former prime minister. This might be the time to return, then, to the Met's internal review of Operation Ribble, the cash-for-honours investigation, which was submitted to its supervisory body, the Metropolitan Police Authority, four months after the collapse of that case.

This was how Assistant Commissioner John Yates defended his boss's decision to investigate: "There is a clear requirement for the police to act independently, impartially with the quite proper need to react to well-founded complaints where it is proportionate to do so and there is at least some inference/intelligence/evidence of criminal wrongdoing." Evidence is not strictly necessary, you note; "inference" and "intelligence" will do. As the only intelligence cited in that case was two articles in The Sunday Times that the Scottish MP had quoted, that puts a lot of weight on inference.

So what inferences have the police made in Damian Green's case? Did they infer that, since leaking is against civil service rules, the soliciting of leaks must be a crime, and a public interest defence is a piece of clever sophistry thought up by twisty politicians?

It is a remarkable coincidence that both these intrusions of the police into politics occurred under the leadership of Sir Ian Blair – Green was arrested, with his knowledge, on his last day in office. It would, however, be an inference too far to suggest that Sir Ian wanted to get his own back on Boris Johnson, the Mayor of London, who got rid of him. Or that he wanted to balance his excess of zeal against Labour in Operation Ribble with a bit of anti-Tory excess. (Although he did complain earlier this year that he had not been asked to investigate Derek Conway, the Tory MP who put his student son on the public payroll.)

Sir Ian, who mysteriously still has a reputation as "Labour's favourite copper", made an interesting comment in his last appearance before the Met Police Authority on Thursday. He said the Mayor's expression of no confidence in him was "a very political move, and it's kind of an imitation of New York". Turnover of New York police chiefs, he said, is more than twice that of Met commissioners – "they came and went at the direction of the Mayor". Well, we can see why he thinks that is a problem, but the rest of us might regard New York as a case study in how to cut crime.

We might think that a police force under the firm direction of elected politicians would be rather better than one that spends thousands of person-hours arresting elected politicians.

Yes, of course, there is the pleasant British delusion that the police are impartial upholders of the law, and that to "politicise" the force would be a terrible thing. But the lessons of Operation Ribble and Operation Arrest-a-Tory are that the police – certainly the leaders of the Met – have been "anti-politicised". They have confused the mantra that politicians are not above the law with the kind of anti-politics ideology that suffuses so much of the post-Watergate media. Sir Ian and his senior officers have no idea that elected representatives have a better idea of what constitutes the public interest than they have.

In the cash-for-honours case, they had the advantage that Blair's conduct was reprehensible, even if it were plainly not illegal. They were on the same side as the unholy alliance of right-wing press and liberal left. In the Damian Green case, they find themselves on the opposite side of that same unholy alliance. The right sees an anti-Tory conspiracy; the liberal left regards whistle-blowing as the most noble form of human activity.

In this case, though, the unholy alliance is right. Damian Green's arrest is worse than a waste of police time. It is the intrusion of arbitrary power – although not government power – into the inner sanctum of democracy, the House of Commons.