Smoking is the greatest cause of preventable illness and premature death in this country killing around 120,000 in the UK every year

Yvette Cooper, Public Health Minister

Mr Davis, 37, had been a heavy smoker since the age of 15, but had a major smoking-related stroke in January 2000.

In the advert, to be shown for the first time on New Year's Day, Mr Davis will talk about how his stroke dramatically changed his health and his life.

He says he finds it hard to admit he is now disabled. He cannot work or even carry shopping home for his wife.

And he hopes his story will help persuade others to give up - although they will undoubtedly find it difficult.

Support 'crucial'

According to a survey carried out by Glaxo SmithKline, half of smokers who are planning to kick the habit are worried about their chances of success.

They are concerned about dealing with cravings and other symptoms of nicotine withdrawal, the poll of 4,000 people showed.

It is estimated just 3% of smokers are successful in stopping without help.

A quarter of potential quitters in 2002 said they would go to their GP for help.

But one in four adults hides their addiction from friends and family who could help them quit.

Patches

Many feel people would be "disappointed in them", or feel ashamed because they know smoking is bad for them.

Just under a third feel guilty about hiding their habit, and one in five feel foolish about the deception.

Experts say smokers who do want to stop can turn to health professionals and nicotine replacement therapies, such as patches, gum or lozenges, for help.

Other forms of support, including buproprion (Zyban), a drug which can help reduce withdrawal symptoms, are also available.

Smokers 'want to stop'

Public health minister Yvette Cooper said: "Smoking is the greatest cause of preventable illness and premature death in this country killing around 120,000 in the UK every year.

"We know that over two-thirds of smokers want to give up and the government is doing all it can to help them."

She added: "Last year 132,500 people set a quit date through smoking cessation services and nearly half of those reported that they had successfully stopped smoking."

In December, the government announced �20 m would be invested in NHS Smoking Cessation Services in 2002 to 2003

The NHS Smoking Helpline, on 0800 169 0 169 is open from 7am to 11pm every day. The Giving Up Smoking website is at http://www.givingupsmoking.co.uk/.

Quitline can be contacted on 0800 00 22 00.