AMBITIOUS plans for a four-runway Thames Estuary airport capable of handling 150million passengers a year. and featuring a direct rail link with East Anglia, were outlined yesterday by leading architect Lord Foster.

The airport would be on the Isle of Grain in northern Kent and would have rail connections to the high-speed Channel Tunnel route, the Crossrail scheme under construction in London and the Liverpool Street to Norwich main line.

The unveiling of the scheme, known as the Thames Hub, comes at a time when the Government has ruled out expansion at existing south east England airports, including Heathrow and Stansted.

Lord Foster said: “We need to recapture the foresight and political courage of our 19th century forebears if we are to establish a modern transport and energy infrastructure in Britain for this century and beyond.”

The proposal points out that the planned location for the airport is on the most sparsely populated area within the Thames estuary, with about half the site involving reclaimed land, and that the approach of aircraft would be primarily over water.

It says the airport would offer more international routes than Paris and Frankfurt, enabling Chinese, Indian and Latin American carriers would be able to operate from the UK for the first time and allowing existing airlines to expand their operations.

However, Rodney Chambers, the leader of Medway Council, which includes the Isle of Grain, said yesterday that the site was one of the worst places for a new airport, with the area including a major liquefied natural gas terminal and the London Array wind farm being built nearby.

“This plan is, quite possibly, the daftest in a long list of pie in the sky schemes that have been put forward for an airport,” he added.

The Thames Hub is a rival to London Mayor Boris Johnson’s plan for a Thames Estuary airport relying entirely on reclaimed land, but a spokesman for Mr Johnson said yesterday: “The mayor is delighted that a distinguished figure like Lord Foster agrees that the answer to Britain’s aviation needs lie in the estuary.”