Campaigners opposed to Heathrow expansion have welcomed British Airways’ (BA) view that the airport will never be able to build a third runway.

BA boss Willie Walsh admitted he had given up hope of ever seeing the project get off the ground and his airline was now looking for space to grow at foreign cities such as Madrid.

John Stewart, chairman of campaign group Hacan Clearskies, said: “It now looks as if finally the third runway has been killed off. It’s most enthusiastic backers, British Airways, are now planning for life without a new runway.”

Mr Walsh made his comments at a chief executives’ summit on Tuesday.

He believed the coalition Government’s decision to scrap plans for a third runway at Heathrow meant the project was now “dead”.

Airlines were being forced to look abroad for opportunities to expand due to overcrowding in London, he added.

London Mayor Boris Johnson, who has backed proposals for a new airport in the Thames estuary, described the problem as “pretty serious”.