Plans to bring in drug-drive limits for the first time have moved a step closer.
But the Government is looking again at the proposed legal limit for amphetamine following concerns expressed during the consultation process.
In the meantime, following consultation, recommended limits for 16 different drugs have now been approved.
This means eight generally-prescription drugs and eight illicit drugs will be added into new regulations that will come into force in autumn 2014.
The new rules will mean it will be an offence to be over the generally-prescribed limits for each drug and then drive a vehicle, as it is with drink-driving.
The illicit drugs include cocaine, where drivers will not be allowed to exceed a limit of 10mg; cannabis, where the limit is 2mg, and also LSD where the limit is 1mg.
It had been proposed to set the amphetamine level at 50mg, but the Government said there had been "significant concerns" on the limit .
The amphetamine level was now being reconsidered so that patients who take medicine for attention deficit hyperactivity disorder are not affected.
The prescription drugs for which limits have been set include morphine (80mg) and methadone (500mg ).
Road safety minister Robert Goodwill said: "The results of the consultation is sending the strongest possible message that you cannot take illegal drugs and drive.
"This new offence will make our roads safer for everyone by making it easier for the police to tackle those who drive after taking illegal drugs.
"It will also clarify the limits for those who take medication."