This is new proposal to be announced in the Queen's speech about planned legislation for the new session of Parliament, which takes place tomorrow. Currently, there is no specific offence for driving while under the influence of drugs. While offenders who drive dangerously or cause injury to other drivers or pedestrians are punished, driving under the influence of drugs is not an offence by itself. In other words, the prosecution has to show that the driver under the influence of drugs has caused physical harm or committed reckless/dangerous conduct in order for the offence to be punishable.

This proposed legislation aims to create a 'drug-driving' charge in a similar manner to the 'drink-driving' charge which is in force now. This would have the result of making driving under the influence of drugs a punishable offence, irrespective of whether any damage was caused as a consequence of driving under the effects of drugs.

This is surely a positive step in preventing unnecessary deaths and injuries on the roads. Drug-driving is identical to drink-driving in the respect that offenders are endangering the lives of others through recklessness, so it would seem appropriate for a similar sanction to apply to both types of conduct.

http://www.guardian.co.uk/society/2012/may/07/drug-drivers-jail-new-law