The Prime Minister has announced his intention to change the law to clamp down on drug-driving.
Under current laws, police have to prove that someone's driving has been impaired adversely affected by drugs in order to prosecute them.
Prime Minister David Cameron insists that this "simply can't be right".
Under the proposed new law, it will be an offence to drive if you have certain controlled drugs in your body in excess of specified limits.
The exact drugs and what levels of them are covered by the new offence will be decided following advice from a panel of alcohol and drug misuse experts and a public consultation.
The proposed new law will carry a maximum six-month jail term, a fine of up to £5,000, and an automatic driving ban of at least 12 months.
Road Safety Minister Mike Penning said: "Drug drivers are a deadly menace - they must be stopped and that is exactly what I intend to do.
"The new offence sends out a clear message that if you drive whilst under the influence of drugs you will not get away with it.
"We have an enviable record on road safety in this country and I want to keep it that way.
"This measure will help to rid our roads of the irresponsible minority who risk the lives of innocent motorists and pedestrians."
The proposed drug-driving law will mean the police could carry new hand-held drug detection machines as well as breathalysers.
The devices are used to take a saliva sample and they are expected to receive approval from the Home Office by the end of the year.
The law change has the backing of road safety organisation the Institute of Advanced Motorists (IAM), although chief executive Simon Best questioned how driving impairment would be measured.
"While we support the introduction of the drugalyser test and this offence, it needs to be backed up by some measure of impairment.
"Without this, the test could simply catch those people who have used drugs at some point but are not necessarily still impaired by them.
"Impairment as the key factor is also essential in tackling drivers who may have used over the counter or prescription drugs which, while legal, can have an equal impact on driving ability as illegal ones."
Cannabis use among young drivers
Research released by the IAM earlier this month found that young drivers are more likely to have driven while under the influence of drugs.
One in ten young male drivers have driven under the influence of cannabis, according to the IAM.
Around 750,000 people have driven under the influence of cannabis and 370,000 have driven under the influence of class-A drugs.
A poll by Confused.com found that 25 to 34-year-olds are most likely to drive while on drugs.
Around 8 per cent of motorists in this age group admitted to drug-driving, compared to an average of 5 per cent across all age groups.
Drug-driving vs. drink-driving
Confused.com explored motorists' attitudes towards driving while under the influence of drugs last August and found that 71 per cent said they wanted the government do more to combat drug-driving.
Around 25 per cent of men and 18 per cent of women polled thought that drug-driving was more widespread than drink-driving on UK roads.
More than a third - 37 per cent - of the 2,000 motorists polled thought that drug-drivers were less likely to get caught than drink-drivers.
But while 25-34 year olds are most likely to drive while on drugs, drink-driving is more common among older drivers.
Drink-driving is most likely among 45-54 year-olds, with 34 per cent of this age group admitting to this, the Confused.com poll found.
What do you think?
Should drug-driving be punished as seriously as drink-driving and do you welcome the government’s crackdown?
Is drug-driving the new hidden menace on our roads or perhaps you feel it’s not a big problem at all?
We want to hear from you! You can share your views on our message board below.