Boris tells Dave to make his mind up over Heathrow expansion.

Boris Johnson has called for the debate over Heathrow's future and alternative airport capacity in southern England to be decided by the end of next year.

Boris said that whilst other countries are moving on with airport capacity London was being left behind.

His comments come as a new modernistic vision for a floating airport in the Thames Estuary has been unveiled by an architecture firm.

Dubbed 'Boris Island' The designs for the 'London Britannia Airport', by Global firm Gensler, show four floating runways anchored to the sea bed, with the option for more to be brought in according to capacity.