A team from the University of Wales found that attempts by doctors to encourage patients to give up the habit during consultations for other health problems were largely pointless.

One 40-year-old man who participated in the study summed up the feelings of many hardened smokers.

Walk out and have a fag

He said: "Everyone knows the dangers of smoking now. It's not like it's a top secret. If that smoker doesn't want to stop smoking, the doctor could be there three hours talking to him and he'll walk out of the surgery have a fag and think, thank God for that."

The authors, writing in the British Medical Journal, found that most people are already aware of the negative effects of smoking and that they believe that it should be up to them whether they give up or not.

In fact, they discovered that the doctor-patient relationship can be damaged if doctors routinely advise all smokers to quit every time they visit the surgery.

Feeling guilty

Smokers are unlikely to heed doctor's advice

Smokers anticipate they will get antismoking advice by doctors when they visit a health centre and they react by shrugging this off, feeling guilty, or becoming annoyed. Some patients were put off going to their doctor for other advice.

The researchers suggest that a better approach is for doctors to be sympathetic and tailor their approach to the individual type of patient rather than preaching messages of doom.

"Doctors should not assume that repeating antismoking advice over and over again for all smokers will continue to be of benefit," the report concludes.

"The oft repeated exhortation that doctors should advise their patients to stop smoking whenever they see them deserves careful reconsideration."

Different types

The study identified three types of smoker.

Contrary - these smokers tend to be less convinced of the merits of giving up, smoked more in response to being told to quit, and anticipated 'ritualistic' advice from health professionals.

Matter of fact - tended to see smoking as a somewhat inexplicable and unfortunate aspect in an otherwise balanced and worthy life. They thought it reasonable that a doctor should discuss smoking, and less likely to be sceptical about the advice.

Self blaming - smokers who feel disgust and self loathing about their habit and reported shame at their smoking causing ill health in themselves and others. They felt doctors ought to speak to everybody about smoking.

Smoking is the single most important remediable cause of premature death in the Western world. For the first time in 25 years its incidence is rising in British men aged 20-24 and women aged 25-34.