Leading article: A clear case of intimidation

It does seem doubtful that the arrest of Ruth Turner at dawn last Friday by the Metropolitan Police was strictly necessary; there can be fewer suspects less likely to abscond than a Downing Street aide. On the other hand, the Metropolitan Police, suspecting a perversion of the course of justice, claim they were merely following standard procedure for such cases. And they can also perhaps be forgiven for acting quickly on the assumption that in political scandals it is very often the cover-up, rather than the original offence, that leads to the breakthrough.

But whatever view one takes of the police's actions, the behaviour of senior Labour Party figures in recent days has been unacceptable. The Culture Secretary, Tessa Jowell, has proclaimed herself "bewildered" by the arrest. Meanwhile, the film producer turned Blairite peer Lord Puttnam ridicules it as "the stuff of movies".

Lord Puttnam is not renowned for his knowledge of police procedures in the real world. And Ms Jowell has not seen fit to involve herself in questions of police procedure before. What justification can she have for getting involved now? In truth, this simultaneous barrage of New Labour complaints against the police suggests something more than a simple concern for Ms Turner's reputation. It smacks of a campaign by Blairite loyalists to intimidate the police.

The Metropolitan Police have every right to be irritated. The officers investigating this high-profile case would not be human if they did not feel an uncomfortable amount of pressure from the fact that senior politicians are publicly disapproving of their actions. As the chairman of the Metropolitan Police Federation, Glen Smyth, has pointed out, decisions on how to conduct this investigation should be left to the police. This bullying behaviour from a party that has put a plethora of criminal justice measures on the statute book and espouses the need for freedom of manoeuvre for the police is rank hypocrisy.

Clearly, the politicians are unnerved - and not without cause. Mr Blair is the first serving Prime Minister to be questioned by police in the context of a criminal inquiry. His close friend and fundraiser Lord Levy was arrested. The same fate has now befallen his "gatekeeper" Ms Turner. Even if no charges eventually emerge, this investigation has already been damaging to Mr Blair's reputation.

But justice should be allowed to run its course unimpeded and free of this political intimidation. There must be no further hint of political interference in this investigation.