Random breath testing is being proposed as part of a crackdown on drink-driving.
At present, the police can breathalyse a driver only following a collision, a traffic offence or if they have 'reasonable suspicion' that the driver has been drinking.
However, a Department for Transport consultation paper set to be released imminently is expected to propose giving police the power to carry out 'targeted breath testing', which effectively means they will be able to test any driver.
Other changes expected to get the go-ahead include the introduction of a new roadside breathalyser that provides instant evidence and removes the need for police officers to take a driver back to a police station for a second test.
In addition, drivers who are only just over the limit will have their present right to demand a second test administered by a doctor or nurse withdrawn. The delay in obtaining the second sample can mean that a drivers alcohol level drops beneath the limit.