Supermarkets caught selling alcohol to minors face having their licences seized from next month.

The get-tough crackdown has been ordered by Sussex Chief Constable Ken Jones who is angry and fed-up with the drink-fuelled crime and yob behaviour.

Some supermarkets have responded by providing more staff training and putting up new signs in their branches.

One has gone up in Tesco in Brooks Road, Lewes, close to the chief's office and force headquarters at nearby Malling House.

It warns that anyone looking under age will need proof they are old enough to buy alcohol.

A spokeswoman for Sainsbury's said they took the issue very seriously and staff were given strict instructions not to sell to under-18s.

Mr Jones has taken his campaign direct to the industry with an article in this month's trade magazine The Grocer.

Mr Jones told The Argus: "Most supermarkets are responsible and have good policies but some do not try hard enough and incrementally allow standards to slip.

"The results are plain to see in that surrounding areas are plagued with drunken behaviour, litter and general disorder.

"This is not good for the stores or their communities.

"We are also aware of quite obvious proxy sales, whereby aggressive under-age youths will approach other customers to buy alcohol for them.

"This can happen in full view of staff as does the post-sale hand-over of the alcohol."

Mr Jones said he was not surprised some supermarkets were selling to minors "given the widespread marketing of alcohol to young people and the considerable profits being made."

He said: "Young people are resourceful and will try anything to get hold of drinks.

"As one sector tightens-up, they will switch to others.

"For example, a well-run off-licence or convenience store will create pressure for nearby supermarkets and vice versa."

Mr Jones said test purchases revealed "widespread failures" by outlets and, he added: "I have witnessed this personally in Sussex."

Mr Jones warned new powers planned for November would be used to punish high street food chains.

He said: "We will be targeting those supermarkets, off-licences, convenience stores, pubs, clubs and bars which we know are a problem.

"The public tells us about those outlets which are a concern to them.

"We analyse data on disorder and yobbery and then the information tells us where we need to concentrate our efforts.

"We will, of course, do all we can to help outlets to improve but they can be assured that we will enforce the law if that fails."

The chief's booze blitz comes amid growing police concern that 24-hour drinking will spark a new wave of antisocial behaviour in towns and cities.

He said: "My message to the trade is please help us to help you by getting your houses in order.

"The people of Sussex, their customers, are fed-up with the low-level yobbery, litter and incivility which results from youngsters getting hold of alcohol.

"All too often, communities are expected to pick up the costs of irresponsible or lax alcohol retailing."