The oldest airport in England could be in for a big expansion under new Government plans.

A Transport Department consultation paper on the future of air transport envisages a new airport on the Kentish marshes at Cliffe.

But if that fails, existing airports such as Shoreham could take more commercial planes.

The report says Shoreham, which last year handled just 924 commercial passengers, could handle up to 500,000 a year.

This was welcomed by Labour councillor Mike Middleton, who chairs the Shoreham Airport Committee.

But it was derided by Green councillors, who said it would be an environmental disaster for coastal Sussex.

Coun Middleton said: "It is something we have always wanted and have been striving for over many years."

Airport manager John Haffenden said it made sense to encourage people to use regional airports.

He said the idea for Shoreham was not to run low-cost carriers such as easyjet. The emphasis would be on scheduled business services.

Mr Haffenden added there would still be a limit to the size of aircraft using the airport.

But Dr Caroline Lucas, Green Euro MP for the South-East including Sussex, was appalled.

She said: "Sussex residents look as though they will end up paying the price twice for the Government's cosy relationship with the aviation industry and its shocking disregard for the heritage, environment and biodiversity of the South-East.

"They will pay the environmental costs of noise and pollution and a 500-fold increase in passengers will bring the already crowded Sussex coast roads to a standstill.

"They will also pay the economic costs of the UK's £6.8 billion annual subsidy to the aviation industry, in the form of tax breaks on aircraft, fuel and tickets."

Transport Secretary Alistair Darling is looking at three main options to cope with a projected 300 million passenger journey increase by 2030.

They are either a new airport on a protected bird sanctuary at Cliffe on the Thames Estuary, or new runways at either Stansted or Heathrow.

But with opposition from environmental, heritage and residents' groups rising, the Government may be forced to abandon the Cliffe option and expand existing airports, including Shoreham.

The consultation document, called The Future of Air Transport in the UK: South-East, says: "There are a number of airports in the South-East that could play a niche role.

"Shoreham was considered to have the runway and land suitable for commercial aviation."

Dr Lucas, who has written a number of reports on the hidden costs of air travel, drew up proposals adopted by the European Parliament in February to force governments to consider the health implications of all new transport projects from 2003.

She said: "Expanding airports to meet rising passenger demand is economically flawed and dishonest.

"Increasing demand is due to low prices, which in turn are available only because the Government subsidises the industry by £7 billion every year."

Coun Middleton said most planes would take off over the sea and there would not be great noise for local residents.

He said: "People need not fear they will get great jumbo jets of the kind that use Heathrow or Gatwick."