Ministers plan sixth terminal for Heathrow

The Government's proposals for a massive expansion of airport capacity in Britain will include the construction of a new runway at Heathrow which could require a controversial sixth terminal.

The Government's proposals for a massive expansion of airport capacity in Britain will include the construction of a new runway at Heathrow which could require a controversial sixth terminal.

The planned third runway at the London airport will be a short landing strip intended for domestic and European flights, leaving existing capacity to concentrate on intercontinental services.

The most likely site for the new runway will be between the M4 and A4 roads and mean the demolition of thousands of homes.

Some senior figures in the industry argue that it will require a new terminal to cope with passengers. It is only eight months since Heathrow's terminal 5 was approved, bringing to an end years of argument and a protracted planning process. A proposal to build a sixth terminal could create an even greater storm – the report into terminal 5 argued strongly against another runway at Heathrow.

A much-delayed consultation paper, to be unveiled tomorrow by the Transport Secretary, Alistair Darling, will also lay out plans for up to two more runways at Stansted airport in Essex, but will rule out any enlargement at Gatwick for the foreseeable future. Most contentiously of all, it will spell out the option of building a new international airport at Cliffe on the Kent side of the Thames estuary, but will also warn that such a project would entail huge spending on infrastructure. The runway at Luton could also be extended to take intercontinental flights, the proposals will say.

Another document will propose a new airport in the Midlands or the expansion of Birmingham airport. Extra Scottish capacity will also be suggested including the possibility of a new airport between Glasgow and Edinburgh.

No major expansion is envisaged in the north of England, except perhaps the extension of existing runways, senior industry sources told The Independent.

Mr Darling will make clear his view that relying on existing capacity in Britain is not an option. But he is unlikely to spell out exactly how far the industry should meet increasing demand which is expected to rise from 180 million passenger flights a year to 500 million.

Consultation on the proposals for the industry over the next 30 years will last until November, which means a White Paper will be delayed until the new year.

Gatwick has been left out of immediate consideration because of a legal ban on expansion, but the decision is likely to mean worse overcrowding at the site to the south of London.

Least likely of the options for expansion is thought to be the new complex at Cliffe which would provoke lengthy litigation by environmentalists. The site is in a protected area, the home of hundreds of thousands of rare wading birds. It is also near a large petro-chemical installation and would require billions of pounds to build new rail and road links.

Andrew McCall of the Airline Operators' Association said he expected the Government to make a strong case for development. "Without expansion the economy will suffer and Britain will lose out in terms of employment. We cannot risk falling behind our competitors," he said.

One alternative to development would be to suppress increasing demand for air travel through taxation. The anti-expansion group Airport Watch argues that the reason the industry is able to expand so rapidly is because it is subsidised by the taxpayer. Airlines pay no tax on fuel, allowing them to keep prices down, it says.