An independent expert has been appointed to examine possible changes to the law on drink and drug driving.

The Transport Secretary Andrew Adonis made the announcement as he launched the Government's Christmas drink drive campaign.

Sir Peter North will advise on the case for changes to the drink driving limit as well as on whether there is a need to tighten the law on drug driving.

For both drink and drugs, the study will also consider the likely impacts of any changes on driver behaviour, and the practical steps needed to support the introduction of any new or revised offence.

The Department for Transport also today launched its £1.2m THINK! Christmas drink drive campaign, including a new Driver Friendly initiative which will see designated drivers at thousands of pubs across the country receiving free or discounted soft drinks.

Adonis said: "Drink driving killed 430 people last year and research suggests drug driving is a key concern for the public.

"To reduce drink and drug driving accidents there may be a case for further strengthening the law. I have appointed Sir Peter North to provide me with independent advice on lowering the drink drive limit and tackling drug driving through a new offence."

North will provide advice on the merit of specific proposals for changes to the legislative regime for drink and drug driving.