Members of an airport watchdog have attacked the findings of a business poll calling for a second runway at Gatwick.

The poll by Sussex Enterprise, comprising 2,700 businesses, showed 87 per cent of bosses questioned believed a second runway would benefit the Sussex economy.

They felt the 40,000 to 45,000 jobs the expansion would create would help the local economy.

But Brendon Sewill, chairman of Gatwick Area Conservation Campaign, said: "We have no unemployment in Sussex so this means we would need to build a new town the size of Crawley to accommodate the extra workforce and their families.

"Another runway could create exactly the opposite effect claimed by Sussex Enterprise. It could lead to a huge labour shortage for firms in Sussex as workers take jobs at Gatwick.

"Some firms could be pushed out of the area as a result because they would no longer be able to compete."

Options for the expansion of airport capacity in the South-East are expected to be announced in May by the South-East and East of England Regional Air Services Study, which was set up two years ago by the Government.

Sussex Enterprise communications manager Steven Gauge said his organisation had taken a random sample of 200 members to discover their views about Gatwick getting another runway.

He said: "We are calling for debate on this issue, not saying a second runway or bust. The benefit to the economy needs to be taken into account alongside infrastructure and environmental issues."

Mr Gauge said the changes in the aviation industry following September 11 meant there was more competition from other airports in Europe.

He said: "Gatwick might not be able to stand still. If we don't have a second runway it could affect competition at Gatwick with airports in Europe."

Cadia, the largest independent association of Surrey and Sussex businesses, is also carrying out a survey of members to find their views on expansion.