Building an airport in Kent would mean Heathrow would have to close, according to a think tank.

The Independent Transport Commission has waded into the debate about the country’s aviation capacity by issuing its own report on what is the best option for expansion.

The report said: “If the UK hub was to be either Stansted or a new Thames airport, we believe Heathrow would have to close as a major airport. This would have massive implications for local jobs and businesses depending on it.”

It added that while the closure would present “huge new economic opportunities”, the airports commission set up by the government “needs to consider very seriously the implications of the closure”.

The commission, which is headed by the economist Sir Howard Davies, is due to issue a report later this year narrowing down the options.

A final report recommending the best course of action for the government is expected after the next election in 2015. MPs on the Transport Select Committee called for the idea of an estuary airport to be dropped in favour of expanding Heathrow.