Ministers have played down a report that they may drastically reduce the drink-drive limit for motorists.
Government adviser Sir Peter North has submitted a report on the issue to the Department for Transport.
According to the Daily Telegraph, Sir Peter recommends cutting the drink-drive limit from 80mg to 50mg of alcohol per 100ml of blood.
However, the Department for Transport said no decision had been made on whether to change existing laws.
The Telegraph says anyone caught above the new limit would face an automatic 12-month driving ban, even if they were only just over the threshold.
The paper also claims Sir Peter has recommended:
- Random breath testing of motorists
- Removing the right to a second breathalyser test at a police station
- A 20mg alcohol limit for inexperienced drivers
- A new offence of driving with an illegal substance in the bloodstream at levels deemed impairing
Sir Peter's report was commissioned last December by Labour Transport Secretary Lord Adonis, but will now be considered by his coalition successor Philip Hammond.
Sir Peter announced he had submitted his independent review of drink and drug-driving laws to the Department for Transport on 21 May.
The government described the Telegraph's story as speculation.
A Department for Transport spokesman said: "We need to tackle drink driving in the most effective way possible to protect law abiding motorists. We are considering Sir Peter's report carefully and will respond in due course."
In an interview with the Sunday Times in March, Lord Adonis suggested Sir Peter was likely to recommend changing the rules.
For the Conservatives, the then shadow transport secretary Theresa Villiers said at the time she was "not convinced that a change would be justified".