A total ban on smoking in restaurants could cost the catering sector $7.9 billion and lead to 21,500 job losses, according to a survey. The survey, unveiled yesterday, was commissioned by the Catering Industry Association and conducted by KPMG Consulting Asia. A total of 819 customers in 145 restaurants, bars, cafes and hotel food and beverage outlets were interviewed in July and August. The survey found that 14 per cent of respondents, mostly smokers, said they would spend less each time they ate out if smoking was banned. Those in hotel food and beverage outlets said they would spend 20.3 per cent less per visit, while those in bars, restaurants and Hong Kong-style cafes would spend eight per cent less. Simon Booker, of KPMG Consulting Asia, said smokers tended to spend 40 per cent more than non-smokers, meaning receipts could fall by 10.6 per cent - $7.9 billion based on last year's industry income. 'It would threaten the viability of some businesses,' Mr Booker said of the ban, adding that about 21,500 jobs could be lost as a result of the fall in revenue. Association chairman and catering industry legislator Tommy Cheung Yu-yan urged the Government not to introduce the ban during the economic downturn. 'Over 30 per cent of our customers are smokers. The matter should be left to the industry,' Mr Cheung said. James Lu Shien-hwai, of the Hong Kong Hotels Association, said the ban contradicted the Government's policy of boosting tourism. 'About 95 per cent of our clients are tourists and most are from the countries with a large population of smokers,' Mr Lu said. The restaurant and catering industry plans to hold a rally on October 2 to oppose the ban. Currently, restaurants with more than 200 seats have to designate one-third of their area for non-smokers. The consultation period on a full ban ends on Saturday.