Six-year-old Ryan claps his hand over his mouth and giggles as he confesses that he likes the idea of smoking. Wriggling with embarrassment in front of his class, he says: “I like the way me dad throws the ciggie on the grass when he smokes outside our house.”

Ryan, a Year 2 pupil at St Vincent de Paul RC primary school, in a deprived ward of central Liverpool, is the only child in his class to admit he is pro-smoking. But figures from a study that started here and in five other primary schools in the city make it abundantly clear that by the time Ryan and his classmates are in their final year at primary school, more than one in three will have tried cigarettes. And, for one in 10, smoking will have become a regular habit.

Fast forward even further and, according to the Office of Population, Censuses and Surveys, of 1,000 20-year-olds who become long-term smokers, 500 will die from smoking-related diseases, while one will be murdered and six will be killed in car accidents.

Liverpool competes - gasping and breathless - with Glasgow for the dubious title of lung cancer capital of Britain, according to the World Health Organisation. It’s a fact of Liverpudlian life that has spurred researchers to carry out a major study of the smoking attitudes of children as young as five; the team has developed a teaching pack, The World of Tobacco, which will be launched in the House of Lords next week.

The initiative started life in the glittering pound;4 million building that houses the Roy Castle Lung Cancer Foundation. Originally established in 1990 as the Lung Cancer Fund to promote research into the causes of lung cancer and carry out a 10-year population study, it quickly acquired an international reputation. But it made a national impact after entertainer Roy Castle, diagnosed with lung cancer in 1992, lent the charity his name before he died. Castle, born and bred in Liverpool but never a smoker, died in 1994, and always claimed he had contracted lung cancer through passive smoking in nightclubs where he worked as an entertainer and trumpeter.

In partnership with Liverpool’s John Moores University, the foundation has tracked 250 children since they entered primary school to trace the development of their views on cigarettes and smoking. The youngsters, now in the first year of secondary education, will be followed until they leave school.

Smoking is big in Liverpool. Outside Lime Street station every young mother pushing a buggy seems to be lighting up. And in a cafe near the Mersey ferry terminal, a small girl pretends to puff on a liquorice stick, just like her mum, who’s puffing away across the table. In parts of the city 40 per cent of adults smoke, compared with a national average of 28 per cent of men and 26 per cent of women.

For almost 80 years, British American Tobacco churned out millions of cigarettes from a nicotine-coloured factory building on the city’s Commercial Road. Before it shut down in the 1980s, women on the assembly lines there (and at two other BAT factories that closed in the 1920s) received a cigarette allowance and could smoke as many as they liked on the factory premises. Thus was a habit ingrained and a public health disaster born.

Christine Owens, smoking cessation expert at the Roy Castle Foundation, co-ordinates anti-smoking schemes across Merseyside and is involved in producing the World of Tobacco packs. She says: “Working with five, six and seven-year-olds, we are not going to see the impact for some time, but doing nothing is not an option. If we are ever going to tackle this issue we have got to do something.”

The need for action has been embraced by Liverpudlians. “The Roy Castle” receives no public funding and gets the bulk of its pound;1 million annual running costs from hundreds of local fundraising events , such as the pound;50 from an OAP swear box brought in every month by a pensioner from a community centre in the Old Swan district.

Six-year-old Colette, a pupil at St Vincent de Paul, is clear about why people start. “You get a lesson how to smoke, maybe from your parents,” she says. Of the 14 children present in her 17-strong class on the day of the TES visit, 11 live in a family with at least one smoker. This school, a world away from the upmarket loft developments that loom over it, may be covered by Liverpool council’s no-smoking policy, but at going-home time the clouds of cigarette smoke wafting into the building from waiting parents is a clue to the kind of air most of them breathe at home.

Dr Lorna Porcellato, who led the early years phase of the research at John Moores University, is convinced of the value of working with children as young as five, although she says the teaching pack is no magic solution.

Her multi-method approach involving questionnaires, interviews and draw-and-write tasks across a range of schools (including St Vincent de Paul) shows that children as young as five are surprisingly well informed about smoking, even if they live in non-smoking households. “I started with a non-smoking population and most of them said it was bad, but we know many of them will end up smoking. We need to unlock that process,” says Dr Porcellato.

James, an earnest-faced six-year-old at St Vincent de Paul, says: “It’s a habit for adults that they do.” So smoking is seen as a proof of adulthood, particularly in deprived areas. As one little boy told Dr Porcellato: “I want to smoke so I will know that I am a dad.”

The trouble is that smoking is seen as cool, as Christine Owens is only too aware. “There is nothing like telling young people it’s an adult activity for making a young person smoke.” She is co-ordinating youth anti-smoking initiatives across the city under the banner of Kats (Kids against tobacco smoke).

A major problem is that so many role models are smokers. Some, such as singer Robbie Williams, actually light up on stage. Ms Owens herself is faced by young people who cannot believe that smoking is as bad as health experts make out; if it was, they say, the Government would ban it.

Teachers such as Eithne Proffitt, who takes Year 2 at St Vincent de Paul, believe the teaching pack will help to change attitudes. “It can give you an unbiased way in,” she says, “because in the end it has to come from the children; we are no longer part of a dumper truck curriculum. Children have to solve things for themselves.”

That makes it all the more important that the message children are getting outside school tallies with what they are hearing in the classroom. The Tobacco Advertising and Promotion Act 2002, which came into force in February, will help; it bans tobacco advertising in newspapers and magazines and at sporting events.

Pop culture can also be used to good effect, as in the Scottish Health Education Board’s most successful anti-smoking campaign so far, which created a spoof girl band called Stinx. The band’s campaign lament, bewailing the difficulty of attracting a boyfriend when you stink of fags, astonished health officials when it made the Top 10 in the Scottish charts.

So, can working with five-year-olds really make a difference in the battle to reduce the number of young people smoking? Anne Charlton, emeritus professor of cancer health education at Manchester University, says new fronts need to be opened. “Unless it is tackled concertedly on three levels - the individual level, the community level through the families and schools, and at the Government level, by pricing and banning advertising - we will get nowhere. On their own, the kids do not have the power.”

All children’s names have been changed