If last night's national response to Sir Liam Donaldson's smoking proposal is any guide, there will be a long and polarised debate before it becomes a part of daily life.

On one hand, thousands of restaurants, bars and nightclub owners were adamant that a ban on smoking in enclosed public spaces would result in an unnecessary and damaging decline in trade.

On the other, charities, doctors and workers' unions said they were convinced the only way to reduce the rising death toll of smoke-related diseases was to impose a ban.

For the hospitality industry, this is an issue that provokes the most ardent of reactions in the light of increased losses caused by a variety of factors from recent dips in tourism to the introduction of the congestion charge in the capital.

Mike Gottlieb, the president of the Restaurant Association, said he was "absolutely certain" a ban would have a deeply damaging effect on its 3,500 restaurant members.

With effective ventilation and a designated non-smoking area, a ban would be unnecessary, said Mr Gottlieb, who owns Café Spice at Tower Hill, and two bars, two restaurants and three cafés at City airport.

"I think both in a personal and professional capacity that a total ban would be absolutely appalling for business," said Mr Gottlieb, a non-smoker.

"Firstly, we do not feel that there is any proof at all that passive smoking can cause harm. Good ventilation and a separate smoking area are more than adequate. Secondly, it is a deeply illiberal move.

"When sufficient steps are taken to protect staff, it must be more unhealthy for them to walk to work in London than work in a restaurant with a smoking section." He added: "I would make an educated guess that trade would drop by between 3 and 4 per cent."

But anti-smoking campaigners have produced research aiming to prove that a ban on smoking in enclosed public spaces is the only option available to the Government.

Seven out of 10 British children are exposed to passive smoking in cafés, restaurants or pubs, says Cancer Research UK. As many as 77 per cent of non-smokers find that a smoky atmosphere causes discomfort, according to Action on Smoking and Health.

While smoking kills an estimated 120,000 in Britain annually, the lives of as many as 165 workers in bars could be saved each year if a ban was in place, TUC research says.

"We would definitely like to see a total ban in workplaces, bars, restaurants," said a TUC spokeswoman. "There is a voluntary code in place within the hospitality industry to lessen the effects of smoking on workers. Some have as a result introduced partial bans and some total bans. But we are convinced this is not enough. There is no adequate regulation in place and only a total ban would protect the health of workers."