Ministers left with the conundrum of where to squeeze extra runways

Three more runways will need to be built at airports in the South-east if Britain is to stop airlines from taking their business elsewhere, the Government has concluded.

Three more runways will need to be built at airports in the South-east if Britain is to stop airlines from taking their business elsewhere, the Government has concluded.

Rod Eddington, British Airways' chief executive, has warned ministers his company might decide to switch its "hub" operations to Schiphol airport, Amsterdam, unless there is a sharp increase in capacity. Such a decision by this country's flagship airline could not be contemplated by any government.

The facts are inescapable. The main five main airports serving London – Heathrow, Gatwick, Stansted, Luton and City – handle more than 100 million passengers a year. The maximum capacity using the six existing runways will be about 160 million, and that limit is expected to be reached by 2010, based on annual passenger traffic growth of 5 per cent.

By 2015, according to the Government, demand for travel in the South-east is expected to reach 184 million passengers, a figure that simply cannot be met by existing airports. Freight traffic is growing at an even faster rate.

The decision last year to approve a fifth terminal at Heathrow means the problem of coping with limited runway capacity will increase. How long the limitation on flights at the west London airport will survive is not clear.

Ministers have cast around for solutions to the dilemma. One option would have been to suppress demand and use airports such as Southampton, Norwich and Birmingham as London overspill sites. The Government has decided to meet demand and has embarked on a consultation exercise aimed at shortening the planning process that led to the longest inquiry in history before approval was given for terminal five at Heathrow.

Environmentalists point out this is not the first time that a government has set out the case for expanding capacity at the three main airports in London and the South-east.

In 1990, the Conservatives set up the Runway Capacity in the South East group (Rucatse) to find ways of accommodating vast passenger numbers.

When the group reported three years later it gave detailed proposals for a new runway at each of Heathrow, Gatwick and Stansted airports, with new terminals for the extra passengers.

Aviation experts believe that little has changed in the past nine years that would cause current Department of Transport planners to reach a different conclusion about the best location for their three extra runways.

At Heathrow, the Rucatse report recommended a "doomsday scenario" involving a new runway parallel to the existing two but situated about a mile to the north between the A4 and M4.

The plan would entail the compulsory purchase of hundreds of acres of land beyond the airport's existing boundaries into an area with an estimated 10,000 inhabitants.

Thousands of homes, hotels, pubs and industrial estates in the areas of Harmondsworth and Sipson would have to be demolished to make way for the new runway. The existing A4 would cease to exist.

But the public outcry and cost surrounding such a radical and costly scheme are widely believed to make a full version inconceivable.

Instead, the airlines have put forward an alternative plan to build a shorter runway to the south of the existing landing strips and still within Heathrow's boundaries.

The new runway would be about 2,500 metres shorter than the other two but would be able to take all short-haul jets, thus freeing capacity for larger aircraft on the main strips.

Even allowing for the 900m separation required between runways, backers of the scheme say it would entail the demolition of fewer than 100 homes. Little is said, however, about the increase in noise.

At Gatwick, a new runway could be built about two miles north of the existing terminals. Although situated mainly in open countryside, it would leave the Sussex village of Charlwood almost surrounded.

Stansted, widely believed to be the favoured option for expansion, would have a second runway built to the south of the existing one, squeezed between the Essex villages of Takeley and Molehill Green.

The landing area would cut between the terminal and access roads leading from the M11 and the A120.