BAA has revealed early stages of a proposal to demolish Terminal 2 and the Queens Building. It wants a single facility to handle up to 30 million passengers. It must first win the approval of the Civil Aviation Authority.
This will involve talks with airlines to assess the viability of the £1.5 billion project.
BAA claims that the scheme would create a better shopping experience and help the airport to meet lower energy use targets. The operator has already secured support from Virgin and Star Alliance, which together with British Airways account for 80 per cent of Heathrow Airport's customers.
HACAN Clear Skies chairman John Stewart commented: "BAA has never been clear as to whether it favours developing a third runway at Heathrow, but at the moment the idea is on the back burner. It recognises that there would be problems with air pollution, knocking down 700 homes and with the huge amount of extra traffic that it would generate. That is why we feel that rebuilding Terminal 2 could be a fail-safe device."
A Heathrow spokesman said: "We are not increasing airport capacity. This is about providing a better terminal experience for passengers, the airlines and our staff."