Image copyright Science Photo Library Image caption The kits will test for cocaine and cannabis, the Home Office said

Detection kits which test if drivers have taken certain illegal drugs will be available to police in England and Wales in the coming days after ministers approved their use.

Analysis of saliva will show whether a driver has taken cocaine or cannabis, the Home Office said.

If the test is positive, police will take a suspect to have a blood test, administered by a medical professional.

A Home Office spokesperson said the technology was "groundbreaking".

'Drug menace'

Policing minister Mike Penning approved the tests this week.

"The government is determined to drive the menace of drug-driving from our roads," a Home Office spokesperson said.

"Not only do those who get behind the wheel while under the influence of drugs put their own lives at risk, but also those of innocent motorists and their passengers."

Image copyright PA Image caption The test will be deployed alongside breathalysers which are used to detect the presence of alcohol

Forces will be encouraged to use the devices "as quickly as possible", the spokesperson added.

Drug-driving is estimated to cause around 200 deaths per year, the Department for Transport said.

A new law, which comes into force in March 2015, makes it illegal to drive with certain drugs in the body over a specified limit.

Currently, police have to prove the driver was impaired due to drug use.

The test will be used alongside breathalyser equipment, which detects the presence of alcohol in a person's breath.

Studies on the influence of cocaine indicate drivers are impaired when they have taken the drug in high doses and during withdrawal periods.

It is thought by the government that cannabis impairs co-ordination, visual perception, tracking and vigilance.