Boris's 'fantasy island' not credible option, says minister

"The problem there is we're starting from where we are. Immediately post-war it would have been very sensible to build an airport in the Thames Estuary. Indeed all the way through until the Seventies this was regarded as a credible option."

He revealed the Government consulted on the idea, dubbed "fantasy island" by Mr Johnson's critics, in 2003 but it had been "heavily" recommended against because of the cost, risk of bird strike and the impact on existing job and the environment.