If adopted, the guidance - which clarifies how existing health and safety law should be applied - will mean offices, factories and workshops should become no-smoking zones, although employers will be allowed to provide smoking rooms.

However, it will not require pubs and restaurants to ban smoking, just to reduce employees' exposure to passive smoking as much as possible.

This could take the form of improving ventilation and making bar counters no smoking areas.

Public health measures

The government's recent White Paper, Smoking Kills, proposed a voluntary code for the hospitality industry to reduce customer and staff exposure to passive smoking.

Critics accused the government of lacking the courage to impose a blanket ban on smoking in public places.

The new guidance, however, would put a legal requirement on the owners and managers of restaurants and pubs to reduce the effects smoke pollution.

At the moment it is at the consultation stage, with the Health and Safety Commission (HSC) having published a draft Approved Code of Practice.

'Clean air'

Action on Smoking and Health said the guidance was good news for smokers and non-smokers alike, as it would help the former to give up and the latter to breathe clean air.

Clive Bates, director of the organisation, said the guidance would force employers to act.

Clive Bates called for acceptance of the proposed guidance

"Even in places like pubs or restaurants, where there won't necessarily be a complete ban, the employer will no longer have the 'do nothing and ignore it' option," he said.

He said people with respiratory problems would also benefit.

"Two million adults in the UK have asthma - for them passive smoking can have an acute and traumatic impact and they should not have to face this risk at work or be barred from certain kinds of job.

And he denied the guidance was an attack on smokers' rights.

"Tobacco industry groups claim that this infringes smokers' rights, but non-smokers have a right to clean air and where there is a conflict, they should come first," he said.

"It is the smokers that are causing the problem by filling the air with smoke."

'Protect smokers too'

However, Simon Clark, director of the smoking rights group Forest, disagreed.

"An employer's duty is to ensure the welfare of all his employees, and that includes smokers," he said.

"A ban on smoking should therefore be a last resort, not a first option as proposed by the HSC.

"More worrying is the very real threat to smokers' jobs. If you were an employer and you know that employing a smoker, who would you employ - the smoker or the non-smoker?

"The logical conclusion is not to employ anyone who smokes."

He also called on full exemption for the hospitality industry, saying there was no need for it to be included in the current proposals unless there was "a hidden agenda" to target it at a later date.

Public Health Minister Tessa Jowell said: "This is an important contribution to our drive to reduce people's exposure to environmental tobacco smoke.

"Far too many employees are still exposed to tobacco smoke at work, despite existing guidance on passive smoking in the workplace."