The Independent highlights a new wheeze for attacking drug users:

Motorists who take drugs face 'zero-tolerance' policy

A policy of "zero-tolerance" towards motorists who take drugs and drive is being considered by the Home Office.

Drivers caught with traces of drugs in their bodies, even if their driving is unaffected by the illegal substances, would be punished, under the tough proposals by police chiefs.

At the moment, apparently, police have to use some physical tests to see whether the drug is impairing fuction - presumably a little like the old "go along the white line with your left hand on your nose please sir" type tests.

Now yes, whatever I think of the stupid drugs laws in this country the substances they are talking about are illegal and you can be done for possession and use of most of them. But what if they are not affecting one's ability to drive? What if you have taken, like US pilots in charge of millions of pounds of flying battleship, something illegal to the rest of us to keep you alert, for example?

And, if they are not impairing your driving, why would you be pulled over in the first place? Or are we talking about random testing in town centre car parks late at night? But if you can't prove it actually is impairing a driver's function I don't see why they should do you for any more than the regular use and possession charges that would apply to each drug.

Oh, and I assume this will apply to those tested prescription drugs that advise against driving because they have been proven to impair function and reactions. Oh no. Of course. This is just another attack on illicit drug users. Not a road safety campaign.