Reports that a new runway is to be built at Stansted airport to ease air traffic congestion in southern England have been dismissed as speculative.

The Independent newspaper said the Essex airport runway was "virtually certain" to be chosen from several schemes under consideration.

But a spokesman at the Department of Transport said "no decision has yet been taken".

Airport operator BAA, which runs Stansted, also said "nothing is decided".

Passengers passing through UK airports

1995: 129 million 1998: 160 million 2000: 180 million

BAA said it was eagerly awaiting a consultation document laying out all the options, due to be published by new Transport Secretary Alistair Darling before the end of the year.

Tourism and business groups said an effective strategy for dealing with increased demand was essential.

But environmental groups have vowed to oppose any scheme involving the building of new runways or airports.

'Easier option'

Air passenger numbers are projected to double within 20 years, and several schemes are under consideration to ease pressure on the five existing London airports.

Projected passenger numbers

2005: 228 million 2010: 276 million 2015: 333 million 2020: 400 million

The Independent said internal advice to Mr Darling said the Stansted runway would be one of the easier options as the surrounding area was sparsely populated.

The advice also pointed out that Stansted has relatively good road and rail links with London.

Environmental groups said the government should try to reduce demand, rather than aim to reach it.

If the price of air travel truly reflected the impact on the environment, people would think twice about flying

Friends of the Earth

Neil Verlander of Friends of the Earth told BBC News Online he would rather see greater use of technology such as telecommunications to reduce the need for flying.

He also wanted the government to stop "subsidising" air travel by making airlines pay fuel duty, so the cost to the passenger would increase.

"If the price of air travel truly reflected the impact on the environment, people would think twice about flying," he said.

But the Freedom to Fly Coalition, formed from business, air user, tourism and trade union groups, said the government must ensure "sustainable growth".

Director Joe Irvin told BBC News Online: "It's no good waiting until we're full and then wondering what to do. We've got to plan ahead."

New airport

He pointed out that even a tax on plane tickets may not have much impact on the burgeoning demand for flights.

"Studies show that a tax of �15 would reduce demand by 10%. But if demand is due to double in 20 years, that won't make much difference. On any reasonable assessment, we need more infrastructure."

Other proposals being considered by the government reportedly include the controversial suggestion of a new airport, with space for four runways, on marshland at Cliffe in Kent.

It's no good waiting until we're full and then wondering what to do

Freedom to Fly Coalition

Some analysts have suggested that one new runway may not be enough, and that one more each at Heathrow and Gatwick would also be required.

The transport department spokesman said the consultation paper had not yet been drafted, so he could not confirm which options were under consideration.

The consultation paper will lead eventually to a White Paper establishing national air strategy for the next 30 years.

The paper had been scheduled for later this year, but it has been delayed by the resignation of Mr Darling's predecessor Stephen Byers.