However, in seasonally adjusted terms, which give a better picture of the overall trend, the volume of sales fell 0.5 per cent during the three months to the end of October from the previous period.

After steep rises in the immediate wake of Sars, increases in the seasonally adjusted volume figure have flattened out in the second half of this year, bearing out forecasts of a gradual slowing of growth into next year.

'The retail trends remain fairly robust but going into next year we are likely to see some easing,' said Standard Chartered Global Markets economist Mike Moran.

'We cannot maintain year-on-year growth of 7 to 8 per cent indefinitely.'

While the expansion of the individual travel scheme had helped drive sales, he doubted increasing the maximum amount of money mainland tourists were allowed to bring in would add much to growth.

'It must be said there is a very strong likelihood that most of the visitors from the mainland already exceed the limit, so the marginal effect of that increase is likely to be pretty slight,' Mr Moran said.

City University professor of economic development Francis Lui Ting-ming said he felt the impact of mainland tourists had been overstated.

'It's less than half a per cent of additional GDP growth,' he said. 'And much of this money will be used to buy imported goods, so while it helps boost sales, Hong Kong people do not really benefit from it. However, psychologically it helps people.'