Facing an epidemic of youth binge drinking, the mayor of London and other officials are backing a call for supermarkets and other "off-license" alcohol retailers to refrain from selling beer, wine and liquor to customers under age 21.

The Daily Mail reported July 17 that the voluntary program was developed by officials in London's Borough of Croydon and endorsed by London Mayor Boris Johnson.

A pilot program in the town of Armadale in Scotland, where alcohol sales to teens were banned on weekends, cut the rate of assaults and vandalism. In Croydon, bars and clubs have also voluntarily stopped selling to customers under age 21. The legal drinking age in Great Britain is generally 18, although youths younger than that can legally drink in some settings.

"I do think that we have got a huge problem with binge drinking, underage drinking and general abuse of alcohol in this city, and I certainly think that this idea is a very interesting one," said Johnson. "Where we have got particular problems in particular areas, off-licences and supermarkets should stop the sale of alcohol to the under-21s."

However, Frank Sodeen of the group Alcohol Concern warned that, "There is a risk that this would alienate people, and it is also difficult to see how it would work unless every shop agreed to take part. Otherwise 20-year-olds will find it pretty easy to find the places where they can still buy alcohol."