The Government has ruled out building a second runway at Gatwick before 2019. However, while business leaders praised the Government for keeping its development options open, opponents said uncertainty remained.

The prospect of expansion at Gatwick airport still looms despite the Government's White Paper ruling out building a second runway for the foreseeable future.

Transport Secretary Alistair Darling opted to honour a legal agreement made in 1979 between airport operator BAA and other parties which bans development at Gatwick before 2019.

However, land at Gatwick will still be put aside, in case strict noise and pollution controls relating to a third runway to be built at Heathrow cannot be met.

The Government backed a new runway at Stansted airport by 2011/2012 and an extra, short runway at Heathrow after that.

It also supported a new runway at Birmingham airport, possibly in 2016, and another runway at Edinburgh airport, possibly by 2020.

However, the most dramatic option for two new runways at Gatwick - increasing capacity to 115 million passengers a year - was ruled out.

With nearby towns, villages and green belt land, the physical constraints as well as the threat of noise and pollution argued against further development.

But by safeguarding land for a possible second runway, opponents said they will have to remain vigilant in case Heathrow fails to meets its conditions - an eventuality campaigners against further expansion at Heathrow are confident of.

Gatwick had originally been excluded from the Government's expansion plans but was reinstated on the orders of a High Court judge following legal challenges by councils in Kent and Essex.

Brendon Sewill, chairman of the Gatwick Area Conservation Campaign, said although the Government had been forced to consider expanding Gatwick, he sensed no desire for it to do so.

He said: "We are relieved Gatwick is not in the front row for another runway.

"But we are certainly not celebrating because we realise the huge environmental damage that will be caused at Stansted.

"We can understand why the Government wants to keep the options open at Gatwick but it's going to cause huge blight as people are still uncertain of the future."

Council officials in West Sussex have criticised the Government for ring-fencing land, which they would rather use for building homes.

Tex Pemberton, West Sussex County Council Cabinet member for highways and transport, said: "It is good news the Government has said it will not overturn the legal agreement.

"But we're not out of the woods yet and Gatwick continues to face another two decades of blight and uncertainty.

"What we will have to do now is press the Government about its decision to ring-fence land in the north-east of the county."

He said the White Paper was contrary to previous Government statements, adding: "We cannot afford to rest on our laurels until the threat is removed entirely.

"We will continue to oppose any hint of extra runways, should they be proposed.

"The overwhelming arguments against any extra runways will be just as valid in 20 years' time as they are now.

"We have always supported expansion at Gatwick using just the existing runway and two terminals. Even the Government forecasts a 50 per cent growth at Gatwick without laying one extra inch of tarmac.

"If Gatwick is allowed to expand without extra runways, time will prove us right."

After months of consultation and speculation, the 173-page White Paper details the Government's plans for dealing with the expected sharp rise in air travel in the next 30 years.

Demand for air travel in the UK is expected to treble from 180 million to 500 million passengers a year.

With the majority of UK and international air travellers using airports in the South-East, the White Paper concentrated on the region seen as the key to expansion nationwide.

In Sussex, Conservative Wealden MP Charles Hendry said the Government was right to honour its commitment not to expand Gatwick before 2019.

He said: "A new runway would involve an extra 100,000 jobs at Gatwick, which in turn would have required a further 90,000 houses locally - on top of all the additional houses we are already being required to take.

"Because so much of the land locally is protected, this would have involved vast building programmes across rural East Sussex, which we simply could not accommodate."

Businesses in Sussex gave a cautious welcome but congratulated the Government for not ruling out expansion, which they view as crucial for the county's economic prosperity.

Mark Froud, chief executive of Sussex Enterprise, said: "By safeguarding land for a new runway at Gatwick, the Government has safeguarded the economic future of Sussex in the longer term.

"Businesses in Sussex have never called for the legal agreement to be torn up. However, we wanted to keep our options open so that Gatwick can expand in the future.

"There will always be local opposition to development but sometimes you have to stand up and do something brave that will benefit the wider community."