Plans are being drawn up to build a 24-hour airport off the coast of the Isle of Sheppey.

According to national media reports London Mayor Boris Johnson's officials are proposing to build the airport on an artificial island in the Thames Estuary off the Isle of Sheppey.

It would provide an overflow for London's Heathrow Airport, which Mr Johnson is reported to have called a "planning error of the '60s".

The airport would be a four-runway hub off the coast of Sheerness which could be expanded to six runways.

If plans went ahead the airport would be built near the site of the wreckage of liberty ship SS Richard Montgomery, which sank off the coast of Sheerness in 1944 carying a cargo of munitions.

Around 1,500 tons of explosives are still on board the wreckage.

A spokesperson of the Mayor of London said: "The Mayor is keen to know what the alternatives are to expansion at Heathrow and would like to know whether the idea of a new airport in the Thames estuary would be viable or not.

"He therefore wants to undertake a study to establish the feasibility of the idea once and for all and is in the process of examining the best way to take the study forward."

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