A funding plan for a new hub airport in the Thames Estuary has been shot down by the owners of British Airways and Heathrow.

Willie Walsh, chief executive of BA parent International Airlines Group, and his BAA counterpart Colin Matthews both attacked the scheme put forward by architect Lord Foster.

Walsh told the Financial Times: “The idea that airlines currently operating at Heathrow would fund the development of an airport that they are not going to use, to the tune of £8 billion, is crazy . . . and we will fight it.

“If Foster has this plan, let him put this plan together without relying on the funding that is provided at Heathrow. Because the airlines operating at Heathrow have not committed to go to this new airport and won’t commit to going to this new airport. That is the bottom line.”

Walsh said the UK needed a four-runway hub airport in the long term, adding it may not be possible to locate it at Heathrow. The best interim solution to the UK’s capacity squeeze was to build a third runway there, he said.

BA has its main base at Heathrow and pays more than half of the landing charges at the airport.

Matthews questioned whether £10 billion could be raised by closing and redeveloping Heathrow, as the Lord Foster plan suggests.

He predicted west London would be hit by a property glut if Heathrow was shut down and that foreign companies that put their European headquarters near the airport could seek to move.

Matthews said BAA’s parent Ferrovial was not interested in the idea of relinquishing the airport in exchange for a controlling stake in the new hub.

“To take an interest you have to think it is going to happen, and we don’t think it is going to happen,” he told the newspaper.

Lord Foster’s plan calls for a four-runway hub airport on the Isle of Grain in the Thames Estuary.

The £33 billion new airport funding model is based on £8 billion taken from landing charges levied on airlines using Heathrow between 2018 and 2028. Another £11 billion would be raised through landing charges levied at the new airport in the decade after its opening, which is proposed for 2028.

The closure and redevelopment of Heathrow would secure £10 billion and a further £4 billion would come from the development of land around the new airport for support facilities.