Health campaigners certainly believe there is a link. It is no coincidence, they argue, that children tend to smoke the most heavily promoted brands.

The European Union is also persuaded that a link exists and will introduce a ban on all tobacco advertising. Although, the directive will take several years to implement and Mr Schumacher can continue to drive his mobile billboard for cigarettes until 2007.

The tobacco industry hotly disputes the notion that advertising can set youngsters on the path to addiction.

It says that people are already sufficiently aware of its products to decide whether they want to smoke or not. There is certainly some weight to this argument. In the second half of the 1970s, for example, advertising activity increased while cigarette sales fell.

The industry argues the millions spent on advertising are aimed directly at those who already smoke in an attempt to try to get them to switch brands.

International comparisons

You would think the arguments could be settled by looking at the smoking trends in countries that have already taken the step of banning tobacco ads. But the evidence is far from conclusive and even contradictory. For example:

• Norway introduced a ban in 1975. The proportion of daily smokers aged 16-19 fell from 37.6% in 1975 to 21% in 1994. But the consumption among adult women increased marginally - from 31% to 34%.
• In the UK, average cigarette consumption per person per year is lower than in France where advertising is banned.
• Smoking is more common among young people in Finland where tobacco advertising is banned than in Germany where it is permitted.

It is always very difficult, even pointless, to compare the experience of different countries. Each has its own attitudes and customs. Crucially, each has its own taxation system; the high level of tobacco duty in the UK has probably done more to persuade smokers to quit than any public health campaign.