Plans for a Thames Estuary airport were first proposed in the 1970s. But the idea was given new impetus five years ago by the London Mayor, Boris Johnson who proposed an airport off the Isle of Sheppey.
The architect Lord Foster suggested a hub airport on the Isle of Grain and there's even a proposal to build at Goodwin Sands, near Dover.
Our reporter, John Ryall has been in north Kent to find out what people there think.
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