The move is part of an unprecedented campaign against smoking that includes proposals to put graphic photographs of the damage cigarettes can do to the body on packets, and giving GPs incentives to help their patients to stop.

Smokers have been spending their last new year indulging in the habit in bars and clubs before the ban on smoking in public places comes into force on July 1.

The Government has pledged to cut smoking levels from 28 to 21 per cent of the population by 2010. It claims that raising the minimum age to 18 will save 1,700 lives a year eventually. Surveys have shown that 9 per cent of 11 to 15-year-olds in Britain are smokers. Someone who starts at the age of 15 is three times more likely to die of a smoking-related cancer than those who begin in their late twenties.

But the Government’s own research suggests that the benefits of the move will will take “a lifetime to come through” and have only a limited impact in the short and medium term.

According to the Department of Health, raising the age will reduce the number of cigarettes smoked by under 16s from 600 million to 515 million. It predicts that large numbers of young people will turn to friends and family to supply them with cigarettes, and in the long term there will be a reduction in adults smoking of just 0.5 per cent, or one in 200.

“There is little conclusive evidence that a higher minimum age alone has an impact on reducing smoking prevalence among young people,” the Department of Health consultation document admitted.

A report by the World Bank echoed this conclusion. It said: “There have been a number of attempts to impose restrictions on the sale of cigarettes to teenagers in high-income countries. In their existing form such restrictions have not been shown to be successful.

“In general, youth restrictions are difficult to enforce, especially given that young teenagers often obtain cigarettes from their older peers and, sometimes, from their parents.”

Raising the age limit would also deprive the Exchequer of up to £45 million a year, health officials have calculated. However, in the same consultation document the Government predicts that the move will save 1,700 lives eventually, saving the NHS £6 million and the wider economy £226 million a year. But it adds that “the full effect of prevalence would take a lifetime to come through”.

Vivienne Nathanson, head of science and ethics at the British Medical Association (BMA), said: “The new limit is only going to be effective if it is properly enforced and part of a broad set of actions designed to discourage young people from starting to smoke.”

At the moment it is not illegal for under 16s to smoke cigarettes, nor is it illegal for friends or relatives to buy tobacco on behalf of under-age smokers, and this is not set to change. However, it will be illegal now for shops to sell tobacco to under 18s, with a maximum fine of £2,500.

Caroline Flint, the Public Health Minister, who pushed through the ban on smoking in public places, said that the move — to be introduced in England and Wales on October 1 — was necessary to protect young people. “Buying cigarettes has been too easy for under 16s and this is partly due to retailers selling tobacco to those under the legal age,” she said. “The law change demonstrates our determination to stop this.”

The Government hopes that raising the minimum age will mean retailers insisting on the same level of proof required for buying alcohol.

The decision to raise the age limit from 16, which was first introduced in 1908, will be accompanied by an antismoking advertising campaign. The decision brings England and Wales into line with the United States, Canada, Australia, New Zealand, the Irish Republic and Spain. The limit in France, Germany, Italy and the Netherlands remains at 16.

NHS and government buildings also become smoke-free from today.

Lights out

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