Many smokers want to quit

On No Smoking Day, campaign director Ben Youdan said a ban in all workplaces - including bars and pubs - would save 4,800 lives a year in Britain.

This compared with 3,400 people killed on the roads each year.

Despite growing pressure for a ban, ministers have not expressed support for the idea.

I gave up for three months, but as soon as I went back in the pub, that was it, started smoking again. Respondent to No Smoking Day survey

A new private member's Bill to restrict smoking in public places will be introduced in the House of Lords on Wednesday.

The Bill would prevent any employee from being contractually obliged to work in a smoking area.

It would also give statutory backing to no-smoking areas in enclosed public places, including bars, pubs and restaurants.

And it would allow the government to set maximum permitted exposure levels to environmental tobacco smoke for both employees and members of the public.

Impact in London

Separate research, released on the same day by campaigning group SmokeFree London, found that almost one in four (23%) of men's deaths and one in eight women's deaths in the capital is linked to smoking.

This amounts to 10,500 deaths in those aged over 35 each year.

The report, published with the London Health Observatory, also found that people with diseases caused by smoking took up 1,100 of the capital's hospital beds every day.

This is the equivalent of almost filling both Guy's and St Thomas's hospitals - and costs the NHS in London at least �2m every week.

Mr Youdan estimated that a workplace ban would lead to 500,000 people giving up the habit, and would have four times more impact on current smoking levels than last year's tobacco advertising ban.

At work, everyone who comes in smokes, and even when I was trying to pack in, they were offering me tabs all the time. Respondent to No Smoking Day survey

He said: "85% of former smokers actually support smoke-free public places because they fear that the tobacco temptation will be too great.

"We know from our research with smokers themselves that the pub is one of the times they're most at risk of relapsing."

Huge impact

Dr Bobbie Jacobson, director of the London Health Observatory, said the scale of the impact of smoking on people's health in the capital was "shocking".

"Our findings show that we must re-double our efforts to tackle the health divide caused by tobacco where the poorest smokers suffer most."

Dr Konrad Jamrozik, professor of Primary Care Epidemiology at London University's Imperial College, added: "This report shows that tobacco is still the major cause of premature death in this city.

"While road traffic fatalities occur on London's busy streets at a rate of under one per day, one Londoner's life is stubbed out by smoking cigarettes every hour."

Draconian idea

Simon Clark, of the smoker's rights group Forest, said the London Health Observatory study had hugely over-estimated the risk to health of smoking.

He also said that most people did not support the concept of a "Draconian" ban on smoking in all pubs and bars.

"There is no overwhelming public demand for a ban on smoking in pubs and restaurants, this is being driven by a handful of obsessive anti-smokers," he told BBC News Online.

Mr Clark said there should be a range of smoking and non-smoking facilities. The best way to deal with smoky environments was to introduce effective air filtration systems, not to deny people choice, he said.

Health Secretary John Reid said ministers had recently launched a consultation exercise on how best to improve public health.

No decisions on further measures to tackle smoking - including a workplace ban - would be decided until the results of that exercise had been collated, he said.

"There are very strong feelings on both sides of this argument. We have to find the British way of doing things," he said.

Smoking is the biggest cause of preventable death in the UK, responsible for 120,000 premature deaths a year.

It is estimated that 1.25m of the UK's 13m smokers will try to quit on No Smoking Day.