The group's outspoken director, Dr John Rae, immediately explained that it was not advocating giving five-year-olds a regular tipple, but simply highlighting that five was the minimum legal drinking age.
But it was another bad day for the Portman Group, which has struggled for the last 18 months to maintain its credibility and independence after a series of damaging events.
The group, formed in 1989, is best known for the hard-hitting anti-drink- driving advertisements that appear on the London Underground each Christmas, warning: "Don't drink and drive or you might live to regret it."
It was set up by the major players in the drinks industry as a group embodying "enlightened self-interest". Frightened by the increasingly tough alcohol laws in the US, they decided on self-regulation before the same happened here.
The group consists of the seven biggest drinks manufacturers - Bass, Guinness, Scottish Courage, Allied Domecq, International Distillers & Vintners (IDV), Seagram, and Whitbread - which between them contribute pounds 2m a year. The board meets approximately every two months, with representatives from each group.
Their choice of director, Dr Rae, had been headmaster of Westminster School for 16 years. He was best known as someone who believed that public schools were socially divisive while arguing it would be a breach of human rights to abolish them.
After retiring from Westminster in 1986 he worked for the Laura Ashley Foundation - an educational charity - for three years, which he admits was not much of a challenge.
The Portman Group was. "The contradictory nature of the job and the difficulty of giving teeth to a role that many would regard as a public relations exercise appealed to me," Dr Rae wrote in his 1993 book Delusions of Grandeur. He admits that a generous salary (believed to be pounds 100,000) and perks such as car and health insurance also played a part.
Most of those who have dealt with Dr Rae are quick to praise the work he has done. Stephen Whitehead, director of social aspects at IDV, described him as a "fair, disciplinarian father that has to make decisions to look after our interests. He has to have our support to do it."
Spokesmen for Bass and Guinness were equally laudatory. "John Rae has enough authority and independence to say what he wants," said a spokesman for Guinness. And Ian Morris, director of communications for Bass, added that under Rae's leadership the group had "achieved many objectives to promote sensible drinking".
But events over the past year have undermined confidence in the Portman Group's much-vaunted independence.
The problems began in December 1994, when it was revealed that the group had offered selected British academics pounds 2,000 to attack the findings of Alcohol Policy and the Public Good, by Griffith Edwards, emeritus professor of psychiatry at London University and editor of the journal Addiction. The book concluded that the best way to reduce alcohol abuse was to reduce overall consumption.
Dr Rae defends the group's actions: "It is perfectly proper to pay people who are asked to do a review... We wanted advice on how to counter some of the arguments of the book we regarded as biased. How could we do that if we don't have the experts?"
The group also faced criticism that its funding of the prestigious alcohol research group at Edinburgh University was not well-known. But Professor Martin Plant, who is about to publish a paper on ethics and alcohol research, rebutted such claims, saying the funding was acknowledged on published research and there were no strings.
The lifting of the ban on the advertising of spirits, and the Department of Health's raising of the guidelines for safe drinking, made 1995 a good year for the drinks industry. But last year's big commercial success - alcoholic soft drinks - was another problem for the Portman Group.
Dr Rae spoke out about "cynical attempts to manipulate an immature market''. But public action was largely confined to discussing a government-backed voluntary code of practice designed to reduce teenage drinking. It is expected to be complete by the end of February.
Insiders say that Dr Rae was far more critical in private over the alcoholic lemonades than he was in public. He will only say: "I believe it's better for the Portman Group to make these disagreements clear than pretend that they don't exist."
Another issue where Dr Rae and the brewers look set to collide is plans for 16- and 17-year-olds to be "apprenticed" as bar staff. Dr Rae opposes the measure, saying: "It may be very difficult for 16-year-olds to say no to young people under 18."
The Brewers and Licensed Retailers' Association remains silent on the issue, except to say it has been campaigning for several years and "we are missing out [by not employing them]".
Dr Rae will retire on 31 August. As yet no successor has been decided. But as one observer within the industry commented: "They will have to pick someone very strong. It's in our long-term interests to find someone who is independent and therefore credible."
Dr Rae himself says: "I think you've got to acknowledge the truth if you want to win the argument. I apply exactly the same precepts as I did with public schools; admit that everything's not perfect, and try to improve the situation."Reuse content