In The ComRes survey of 2,000 people commissioned by Medway Council and Kent County Council 38 per cent supported an estuary airport. However, this figure fell to 16 per cent when people are told that existing major facilities would have to close as a result.
The findings come as the London Mayor tomorrow submits his final plans for an Estuary airport to the government's aviation commission.
He has commissioned research from the Civil Aviation Authority showing one million people will be subjected to harmful noise if a third runway is built at Heathrow.
Local councils are opposed to his four-runway Estuary plan.
Cllr Rodney Chambers, Leader of Medway Council which with Kent County Council and the RSPB have opposed plans for an estuary airport, said: “No one disputes the need to invest more in aviation in order to ensure the UK keeps pace with demand and matches competition from abroad.
However, we strongly believe that plans to site a hub airport in the Thames Estuary is financially, geographically and environmentally wrong. It will waste tens of billions of pounds of taxpayer’s money for a project which is on the wrong side of London for the majority of passengers.
“This survey highlights the chronic lack of public support for the project. Most people will not back a scheme which closes other key airports including Heathrow and City and Southend Airports and it’s time we explore other, more sensible options. This should include how Stansted can be upgraded alongside improvements at the network of excellent regional airports which serve the UK and are not being used to their full capacity.”