Road safety minister Mike Penning has announced that drugalysers could be installed at every police station by 2012, but that the first devices could be in use within months. The technology will mean that police no longer have to wait for permission from a doctor before carrying out a blood test that can be used as evidence.

Julie Townsend, campaigns director for Brake, said: 'We’re pleased the Government is taking steps towards stamping out the menace of drug-driving – the introduction of drugalysers is long-overdue.

'However, we need to go further than just introducing testing kits in police stations. In other countries, screening devices are used at the roadside to catch drug-drivers; we need to be moving urgently towards roadside screening in the UK. We also desperately need to close the loophole on drug-driving by making it an offence to drive with illegal drugs in your body, so police don’t have to prove impairment, and we need to step up roadside enforcement. These steps are vital if we are to put a stop to those highly selfish drivers who drive on drugs and wreck lives.'