Scotland and Ireland have done it, and the results have been positive. But what will happen in England in July when the law against smoking in public places comes into effect? Francis Elliott and Nina Lakhani report on the Government's drive to kick the habit

Employers are to be told to give workers who smoke extra time off or cash to encourage them to quit when the smoking ban comes into force in six months' time.

Smokers who won't or can't quit should receive nicotine patches paid for by their firms to help them to cope, according to official guidance being prepared ahead of the ban on 1 July 2007. The instructions from the National Institute for Clinical Excellence (Nice) will be issued as part of the biggest co-ordinated effort launched in this country to drive down smoking rates.

The Government has just three years to meet an ambitious target to reduce smoking rates to just 21 per cent of the adult population from its current level of 24, about 9.5 million people.

To help to achieve its goal the NHS rationing body is also preparing to approve the prescription of a new anti-smoking drug, varenicline, that is twice as effective as current treatments, at least in the short term.

The minimum age at which cigarettes can be bought is also to be raised from 16 to 18 this year to bring Britain in line with a number of other EU countries.

And anti-smoking campaigners are championing the idea of adding 20p to the cost of a packet of cigarettes, a move they claim could lead three times more addicts to quit than the smoking ban.

The experiences of Ireland and Scotland, which have already introduced bans on smoking in enclosed public places, are mixed. Worries about compliance have proved unfounded; the bans have retained public support and there have been unexpected benefits. Hoteliers and restaurateurs, for example, report considerably reduced linen bills now that burns in sheets and tablecloths are a thing of the past.

Perhaps surprisingly the ban has proved almost as popular with smokers as non-smokers in Ireland and Scotland.

For Maureen Moore, chief executive of ASH Scotland, which campaigned for the ban that came into force on 26 March, it has been nothing short of "the public health triumph of a generation".

However, grumbles from the licensing trade are borne out by an independent study that finds that there has been a 14 per cent drop in customers and a 10 per cent drop in sales.

"Our study suggests that the Scottish smoking ban had a negative economic impact on public houses, at least in the short run, due in part to a drop in the number of customers. The short-term impact of the ban did not lead to more customers coming into pubs due to the smoke-free atmosphere and presumably did not lead smokers to spend more money on drink or food instead of smoking,'' say the researchers from University College London, the Institute for Fiscal Studies and London School of Economics.

There is disappointing news, too, for those who hope that the smoking ban will lead to big drops in the numbers of smokers. Speaking of the Irish experience, Professor Luke Clancy, chairman of the anti-smoking group ASH, said: "There was a steeper decline in the year of the ban - something like four times the decline we would have expected. But it is now creeping up again."

Most depressingly, smoking prevalence among young people in Ireland appears to be unaffected by the ban. That's why campaigners such as Professor Robert West, director of tobacco studies at Cancer Research UK, want ministers in this country to give the green light to massive tax hikes.

"The government target [to reduce prevalence from 26 per cent to 21 per cent by 2010] is a big ask which I don't think they're going to meet. The current yearly reduction is 0.4 per cent with current prevalence at 24 per cent. Just do the maths.

"The smoking ban is likely to produce a 0.5-1 per cent reduction, which will give a boost to the numbers. But the Government needs to do something else if it is to reach its target. What we know makes a difference is price. If they put the price up by 5 per cent, we would see a further 1-2 per cent decrease in prevalence straight away."

For the moment ministers remain confident that the smoking ban will provide a trigger for millions of addicts to quit - and clearly hope that employers will do all they can to encourage their workers to quit when the ban comes into force.

Draft guidance published by the Committee on Public Health Interventions, a part of Nice, on 20 December says employers "should provide incentives" to workers who smoke. It also says that firms should provide nicotine replacement patches to offset "temporary cravings" suffered as a result of the ban. It suggests that incentives "could include time off in lieu to attend a smoking cessation course and reimbursement of the cost, if any, of treatment".

That treatment is likely to include doses of varenicline, marketed in this country as Champix. The new drug, which works by blocking the urge to smoke, costs about £50 a month.

Trials of the drug showed that 44 per cent had quit after four weeks - although after a year the figure had fallen to 22 per cent, which is similar to that of other treatments such as nicotine replacement therapy.

But a spokesman for the Forum of Private Business, a body which campaigns on behalf of small businesses in the UK, questioned whether firms should pay for their smokers' medication or provide incentives for them to quit. "This will be a costly burden on small businesses. It is ridiculous that employers should pay for the habits of employees.

"Most employers would support efforts by their staff to quit smoking, but asking them to foot the bill for treatment seems a step too far. It is another example of regulation that burdens business and puts a strain on the employer-employee relationship."

Smoking cessation facilities are some of the best funded in the NHS thanks to protected funding raised from tobacco sales. There are no fears that the clinics will be unable to cope with an expected surge in demand from smokers wanting to quit in advance of the ban. Indeed, some fear that that the facilities are too well funded. Some local health care trusts have been criticised for offering cash bonuses and even holidays to smokers who quit. And last week it emerged that NHS fraud investigators are probing widespread abuses of a scheme that rewards pharmacists who help smokers to quit.

Nevertheless public health officials are determined that 2007 will be the year that the smoke clears. But what - other than bands of hunted-looking hard-core addicts in doorways - will be revealed when it does?

Additional reporting by David McKittrick, Paul Kelbie and Roger Dobson

Lighting-up time: Ah, for those guilt-free days

In 100 years from now, Antiques Roadshow will feature a couple producing an old, shallow receptacle with a wide lip and a groove at each corner. "We found it in the loft," they will say. "What is it?" "Ah," says the expert, "it's an ashtray!" And, seeing the puzzled look on their faces, he will explain that people once "smoked" sticks of tobacco they called "cigarettes". Thus, a habit which enslaved - and killed - millions will have become a historic quirk, as bizarre to 2107's attic-clearers as antimacassars seem to us.

The beginning of smoking's heyday was the 1920s. Until then, 15 American states outlawed cigarettes and some employers refused to hire smokers. In Britain, opposition was never more formal than tut-tutting, but the Great War saw off most critics, and, in the US, Kansas, the last state to have a ban, relented in 1927.

So, with health risks no more than distantly suspected, there followed a couple of decades of ubiquitous, guilt-free smoking. Photographs of social events show virtually everyone with fag 'twixt lips or fingers; the movies taught smoking as an accessory to seduction, and companies such as Philip Morris even sponsored lecture tours which gave women lessons in "How to Smoke". Indeed, smoking was seen as a badge of liberation: witness the march protesting about inequality down New York's Fifth Avenue in 1929 by women carrying Lucky Strikes as "torches of freedom". The gesture may have had rather more force had the event not been sponsored by General American Tobacco.

The habit was so pervasive that Emily Post, Good Housekeeping's font of etiquette, wrote: "Those who smoke outnumber those who do not by a hundred to one. So... it is scarcely fair that the few should be allowed to prohibit the many from the pursuit of their comforts and their pleasures." By 1940, cigarette consumption among American adults had risen to 2,558 a year, nearly six times the rate for 1920, and 10 years later in Britain, fully 80 per cent of British men smoked.

Looking back, it might seem that the thick fug of addiction separated smokers from acknowledging the harm they were doing to themselves. But there was something of a conspiracy afoot, too. The link with lung cancer and heart disease was effectively proven by the early 1940s, but buyers of Senior Service, Kensitas and Capstan Full Strength were not told. Only a brave freelance called George Seldes, in his In Fact newsletter, and Reader's Digest campaigned against cigarettes. The rest of the media, fearful of losing the millions in tobacco advertising, did not print the evidence. Right into the 1950s, the journal of the American Medical Association was carrying advertisements that claimed smoking was healthful.

Then came Surgeon General's reports, and the start of the road to sanity we now travel. Smokers feel persecuted these days. The comforting news for them is that the great anthem of the oppressed - "We Shall Overcome" - was first sung by striking South Carolina tobacco workers. The bad news is that, like the habit itself, it didn't do them much good.

David Randall

Counting the cost

£1.5bn a year is spent by the NHS to treat smoking-related diseases.

90% of lung cancer cases in the UK are caused by tobacco.

6m Britons have died from tobacco-related diseases in the past 50 years.

13m adults in Great Britain smoke, 26% of men and 23% of women.

80% of smokers start in adolescence.

50% of all regular smokers will eventually be killed by their habit.

34m days each year are lost in England and Wales through sickness absence caused by smoking.

1bn people in the 21st century will die from tobacco if current smoking trends continue, say scientists.