A cross-section of Lord Foster's plans for a new Thames Estuary airport

by Dan Bloom

Boris Johnson has revealed he would be prepared to expand Stansted Airport instead of building huge new runways in the Thames Estuary.

But the London mayor, who has long pushed for a Thames estuary hub, insisted that is still his favourite option - despite fierce protests by Medway politicians.

In a fist-thumping speech to businessmen this morning, he claimed the Prime Minister had agreed to fund "proper studies" into Stansted and two estuary hub plans.

It is not clear what form these studies will take, or how they will fit with the government's wide-ranging commission on air capacity.

And he refused to be drawn on Stansted, saying: "I don't want people to think that we're excluding anything today, all we're arguing is there are three solutions."

But by including the Essex airport, the mayor may have found a less controversial way of reducing support for expanding Heathrow - a plan he detests.

He said a third runway at Heathrow would be "obsolete as soon as it's complete", adding: "We don't have a snowball's chance in Hades of meeting the challenge."

Even so, he focused his dreams on the Thames estuary.

The London mayor said rare birds living there "can be relocated in a safe and humane way" and the SS Richard Montgomery, a wrecked ship packed with explosives, "will need to be dealt with anyway."

He dismissed expanding Gatwick, which he said would face "massive opposition in Sussex" and added: "Manston and Lydd are quite far away."

"There's only one problem remaining to address and that is the problem of political will," he said.