Ms Rosewell says it could be built within eight years and be open by 2025 - only a year or so later than a third Heathrow runway would be expected to be in operation.

BBC: Kent island airport 'best solution' to meet flight demand

Ms Rosewell, who runs an economic analysis partnership and holds a number of non-executive directorships, believes it would not take much longer to build than a third runway at Heathrow - one of the other options under consideration.

BBC: Kent island airport 'best solution' to meet flight demand

Ms Rosewell plans to submit her initial proposals to the review being conducted by Sir Howard Davies, who was appointed by the prime minister to investigate potential solutions to the demand for more airline capacity in south-east England.

BBC: Kent island airport 'best solution' to meet flight demand