The material, which has the support of the Home Office, comprises posters, shelf signs and staff badges bearing the Challenge 21 message. Staff are advised to ask shoppers that look 21 or under for ID when buying alcohol.
Retailers involved in the scheme include Asda, Sainsbury's, Somerfield, Tesco, Marks & Spencer and Waitrose. Off-licenses Bargain Booze, Oddbins and Thresher have also signed up, in an effort to target underage drinkers. All the major retailers will have the same signs, to raise the profile of Challenge 21.
BRC director-general Kevin Hawkins said: 'We are working to create a culture in which all young people expect to be challenged when they attempt to buy alcohol. The first step towards creating this culture is effective communication with the target audience. This signage, which we intend to be displayed prominently at all off-licensed shops and stores, will get the message across in a much more forceful and effective way.'
Home Office minister Paul Goggins said: 'The fact that businesses operating in such a highly competitive market have joined together in this way demonstrates the firm commitment of the industry to reduce sales of alcohol to children. The signs will be highly visible at all major supermarkets and will be an important deterrent to those who would seek to purchase alcohol illegally.'