Image caption Hundreds of accidents were caused by drivers influenced by drugs

A testing kit to detect drugs in drivers has been approved for police use across the UK, the Home Office says.

The kit will analyse a mouth swab for traces of cannabis. Testing capability for other drugs is being developed.

It will be used at police stations, and removes the need to have a doctor take a blood sample for drug testing.

During 2011, at least 640 accidents were caused by drug-drivers using both illegal and medicinal substances.

The Department of Transport statistics - the most recent available - included 49 deaths.

Policing and criminal justice minister Damian Green said: "Those who take drugs and go out on the roads are a menace to pedestrians, other motorists and themselves."

The device, made by Hemel Hempstead firm Draeger, was subjected to quality tests by the department's centre for applied science and technology before approval.

The testing kits are being introduced under a wider crackdown, which will see drug driving become a specific offence.

Offenders will face up to six months in jail and a fine of up to £5,000 as well as an automatic driving ban of at least 12 months.

Previously, getting a doctor to the police station and the examination itself both take time - and could mean the drugs have left the suspect's system before the blood sample was taken.

A positive saliva test with the new equipment means officers will be able to ask for a blood sample without seeking medical approval.

Evidence to support a prosecution can only come from a blood specimen.