* The NUT reckons advertisers spend around pound;300 million a year targeting the classroom

* Last year, union members voted to campaign against commercialisation in schools, focusing on adverts for foods high in sugar, salt and fat

* Advertising in schools is legal in England; it’s at the discretion of the headteacher and governors

* The Scottish and Welsh executives have banned branding on school vending machines, which can be a lucrative resource for larger schools, raising between pound;15,000 and pound;40,000 a year

* Cadbury’s scrapped its campaign for free school sports equipment after it was revealed that pupils would have to eat 5,440 chocolate bars - containing 33kg of fat and nearly 1.25 million calories - to qualify for a set of volleyball posts

The battle for children’s hearts, minds and pocket money has been raging for years, with marketing directors trying to squeeze their way into schools, and parents, teachers and health organisations pushing hard to keep them out. But the principle of keeping schools commercial-free zones seems to have weakened in the past few years as more and more companies focus on this increasingly available market. Many schools now have vending machines plastered with adverts and branding. Others have their football teams kitted out in fancy, sponsored strip. Teachers are using commercially branded resources in the classroom and on the sports fields. Schools are collecting vouchers, saved by children and their parents, from supermarkets, cereal packets and crisps.

“There has been a quantum leap in companies advertising in or sponsoring schools and we reckon brands are now spending an estimated pound;300 million a year targeting the classroom - and the Government is encouraging it,” says John Bangs, head of education at the National Union of Teachers.

What is the policy on advertising to children through school?

The Government is taking a hands-off approach in England. Its Teachernet site advises: “Acceptance of advertising, by display of posters, distribution of leaflets or any other direct method, by a school is at the discretion of the headteacher and the board of governors. Should the decision be made to accept advertising in principle, the decision regarding what can and cannot be advertised is also at their discretion.” Nor are there any hints England may follow the Scottish and Welsh executives, which have banned branding on vending machines in schools. However, the recent Commons health select committee report on obesity condemns initiatives to give schools sports equipment or books that require coupons from crisps or chocolate wrappers.

A spokesperson from the Scottish Executive says Scotland introduced the ban as part of its Hungry for Success campaign to promote healthier eating. It starts in primary schools from December this year and in secondaries from December 2006. It’s a move welcomed by some schools because the machines are usually installed by contract caterers and not under the control of the head. “I’d like to ban all the fizzy drinks as well and just sell water,” says Alex Wallace, acting head of James Gillespie’s high school in Edinburgh.

Why do companies want to advertise in schools?

Catching them young is considered a coup in building brand awareness and loyalty, especially as children are rarely as cynical or worldly-wise as adults who have been marketed to all their lives. Companies also count on pester power, when children pressure parents to buy particular brands, and they have their own pocket money to spend.

Are children susceptible?

A recent study by the Food Standards Agency is adamant they are. “Children are bombarded with messages that promote food high in fat, salt and sugar,” says Sir John Krebs, chair of the FSA. “The evidence shows that these messages influence children. Eating too much high fat, high sugar, high salt foods is storing up health problems for their future.”

So is advertising responsible for the spiralling levels of obesity?

The FSA certainly thinks so. It highlighted the growing problem in a report in September last year by Professor Gerard Hastings, from the University of Strathclyde’s Centre for Social Marketing, on obesity and the influence of food promotion on children. It claimed intense advertising was leading children to choose high fat, sugar, and salt options over healthier snacks and food. It also highlighted the serious consequences of those choices.

According to the report, in the past 10 years, obesity among 15-year-olds has trebled to 15 per cent, with mature-onset diabetes, associated with older, indolent adults, now being seen in teenagers. By 2010, a quarter of the adult population will be obese, with the cost to the nation in terms of illness and sick days calculated at pound;3.6 billion.

Who is campaigning against in-school marketing?

The NUT passed a resolution at its 2003 conference to campaign against commercialisation in schools and has since focused its campaign on advertising of foods high in sugar, salt and fat. “What children need is a safe, neutral space at school where they can be educated to make good choices on their own,” says Mr Bangs.

Other seasoned campaigners include the Food Commission, Sustain (the alliance for better food and farming) and, more recently, Stourbridge MP Debra Shipley. Previously intent on getting the advertising of high fat, salt and sugar foods to under-fives banned, she has broadened her scope to include advertising in schools. Her latest success has been to persuade BBC Worldwide to halt any promotion of “treat” foods. This stops any sponsoring of programmes targeted at children and young people, removes any “treat” advertising in BBC publications and stops all joint promotional activities with fast food chains.

Meanwhile, the FSA has produced an action plan aimed at reducing obesity and is looking to schools to help by having more influence over what goes on the front of vending machines as well as what goes inside.

What are the campaigners doing?

The NUT, which is backing Ms Shipley, has produced guidance to all teachers about how far to let companies in. It advises they consider:

* the educational content of materials and reliability of information

* the acceptability of advertising by the sponsoring company

* whether the materials support healthy eating by pupils

* the impact on teacher workload, particularly in terms of the benefit to the school weighed against additional bureaucracy for teaching staff

* value for money

* impact on parents, for example, being pressurised to buy certain products.

“Commercialism of schools has a negative impact on children’s education,” says Kath Dalmeny, policy officer at the Food Commission, which campaigns to keep the issue of unhealthy food alive in the public domain.

But is all advertising bad?

It can bring in much-needed revenue, but campaigners say it confuses children. “Schools are trying to educate children about making sensible choices, but they are being bombarded with different messages through the advertising,” says Ms Dalmeny. “The school accountants may support it, but money is not the most important thing.”

Campaigners and parents are also concerned the UK may go the same way as the United States, with its long history of business involvement in education. In the US, advertising can be found on book covers (more than half of US students, 25 million, received free book covers in 1998 with ads for companies such as Frosted Flakes and Lays Potato Chips); educational posters in hallways advertising sweets; branded menus in school cafeterias; coupons (McDonalds, Pizza Hut, Domino Pizza) for fizzy drinks, chips, burgers and pizzas as rewards for reading; school buses; teaching materials; school websites; sponsors’ logos on sports fields, gyms, libraries, playgrounds and classrooms; school events paid for by corporations; vending machines; and student diaries and other products sold in school to students. In Seattle, a parents’ group successfully campaigned to ban all advertising in its district’s school and is aiming for a state-wide ban.

Can schools benefit from advertising?

Most secondary schools now have vending machines, ostensibly to stop young people leaving the school grounds in search of liquid refreshment, but also to provide cheaper catering facilities. The machines have proved a lucrative resource for larger schools, raising between pound;15,000 and pound;40,000 a year. This month, ministers rejected a proposal to remove these machines after the Commons health select committee said they encouraged unhealthy eating. However, the Government will ask schools to restock the machines with healthier foods, such as milk, fruit and water.

Tesco claims that its Computer for Schools scheme has benefited schools.

Now in its 13th year, the voucher-driven scheme has provided 50,000 computers and more than 500,000 pieces of computer equipment to thousands of schools. “Last year another 1,500 schools signed up,” says a Tesco spokeswoman. “It’s popular because it can provide much-needed equipment. We have developed it over the years by listening to feedback from schools and teachers, and have extended our catalogue of equipment that vouchers can be redeemed against because it’s what the schools wanted.”

Another scheme, Kit4Schools, from Be Sport Ltd, provides free sponsored sports kit. Set up three years ago by ex-professional footballer John Scales to encourage private funding for school sports, it has supplied thousands of free shirts and shorts to schools, which would usually cost up to pound;400 for a team. “The schools benefit by getting high-quality strips and the kids are motivated because they know they look the part,” says the former defender.

Headteachers appear to be open to accepting certain marketing material. “It can be beneficial,” says Ian Foster, head of Leominster junior school in Herefordshire for 11 years. “But you must always weigh up the implications carefully. It cannot be in direct conflict with what the parents and teachers want and expect.”

When hasn’t it worked?

Walkers Crisps, Cadbury’s and Nestle have tried to emulate Tesco’s success with their own voucher schemes. But they have been received with less enthusiasm. “Teachers want schemes that don’t mean extra work,” says David Tuck, head of Dallow primary school in Luton. “We don’t want to have to cut out vouchers from smelly bags or sit and count thousands of vouchers. And we don’t want resource material that takes up a lot of extra time and commitment.”

Cadbury’s quickly scrapped its chocolate for free sports equipment campaign after an embarrassing expose by the Food Commission revealed that pupils would have to eat 5,440 chocolate bars - containing 33kg of fat and nearly 1.25 million calories - to qualify for a free set of volleyball posts.

Can teachers benefit?

Many companies are now looking at creating support materials that will help teachers in the classroom. “There is no doubt that schools benefit from responsible business involvement,” says Nick Fuller, chief executive of Edcoms, an educational marketing consultancy that has worked with British Gas, BT, Woolworths and Weetabix. “But they want business involvement that is developed in consultation with education experts and responds to schools’ needs.”

Edcoms recently developed a resource for Weetabix to support primary schools on their sports days. Energy for Everyone packs include advice for teachers on planning a sports day, free sports equipment for schools (including branded team bibs, finishing tape and a stopwatch), information on how schools can involve the local press in their sports day, and advice for parents on how to get involved. The pack was requested by 48 per cent of primary schools - and even earned the company column inches in the media. Skin and sun care specialist Nivea has produced a health pack to educate teenagers about safe sun, while Proctor and Gamble’s Ariel has developed a sampling pack, Stains and Science, as part of a project promoting science in schools.

Are there any guidelines?

Guidance about advertising and sponsorship in schools can be downloaded from the Department for Education and Skills education business links website (see resources).

Will advertising in schools keep growing?

The Government doesn’t seem to have a problem letting heads decide on the appropriate amount of marketing going on in schools. But the pressure to ban, or at least limit, the advertising of fatty, sweet and salty foods may prove too powerful to ignore, especially faced with the health time bomb of obesity. Meanwhile, the FSA intends to keep the pressure up, as will the NUT, the Food Commission and Debra Shipley.

What moves are advertisers and marketers making to head off opposition?

Coca-Cola announced plans recently to withdraw all branding from its vending machines in British secondary schools - although it claims this is not a change of policy. “Coca-Cola has always had a policy on not advertising to under-12s. We are merely reiterating this,” says a company spokeswoman.

Isn’t it up to parents to educate children in sensible eating?

A recent survey for the TES by Professor Neil Armstrong, director of the children’s health and exercise research centre at Exeter University, found that 79 per cent of parents wanted vending machines in schools banned - although many of these parents are still letting their children consume vast quantities of unsuitable foods outside school. “The problem for the schools is that they are supposed to be educating children about how to make healthy choices while appearing to endorse high fat, high sugar, high salt food by allowing the products and adverts for the products into the school,” says Kath Dalmeny.

Main text: Su Clark

Photographs: Sam Friedrich; AP

Additional research: Sarah Jenkins

Next week: Learning to read