Thousands of breathalysers were made by various manufacturers under licence, increasingly compact and increasingly efficient.

ECONOMIST: Robert Borkenstein

But the Department for Transport said it had no plans to install in-car breathalysers in cars - or to use them to test drink-driving offenders.

BBC: David Nutt suggests alcohol sensors 'in every car'

He said there were no plans to widen the use of breathalysers, but agreed that "irresponsible" sales of alcohol - particularly drinks sold at a loss - needed to be controlled.

BBC: Oral questions

She called for a social strategy - to look at minimum pricing and licensing controls on home delivery alcohol services - as well as criminal justice controls, such as making breathalysers compulsory.

BBC: Oral questions