London Mayor calls for sobriety tests

In a column for The Daily Telegraph​, Johnson proposed that "drunken thugs" could stay out of prison as long as they visit a police station twice a day to take a £1 breathalyser test and prove they are sober.

Johnson likened the proposal to a “highly successful” scheme in America, the “24/7 Sobriety Programme”, which he said had dramatically cut repeat offending and led to a significant drop in the number of people being jailed.

His proposal follows last month's London riots during, which Johnson said “the horror and expense of the current booze culture” was seen throughout the capital's accident and emergency departments.

“If you are convicted of a drink-related violent offence then you may stay out of prison — if and only if you stay off the booze,” said Johnson.

“You may think this is impossible to enforce, but in South Dakota they have come up with a very effective tool. You simply require the individual to take a breath test twice a day.

“You make it a condition of his (and it is normally his) parole that he must report twice a day to a police station and prove that he has not been drinking; otherwise he is arrested and locked up.”

He added: “And it doesn’t cost the state a thing, because you make sure that the — relatively low — cost of the breathalyser is met by the offender."

Johnson also said other programmes to get people off alcohol should be encouraged, such as those championed by Alcohol Concern.

He added: “Alcohol plays a big part in domestic violence; tough anti-alcohol measures can help bring down crime, as we have seen on public transport, where a booze ban has been accompanied by a 30 per cent fall in crime.

“If we won’t lock them up, and we want to cut drunken violence, then sobriety tests must be part of the answer. We need to pilot the scheme now.”