ONLY one in six people back a “Boris island” airport that would entail closing Heathrow, City and Southend airports, according to a new poll.

More than a third of respondents to the survey backed the idea of a new airport on the Isle of Grain, in Kent, championed by London mayor Boris Johnson.

However, support fell to just 16 per cent when respondents were told it would result in the closure of existing facilities.

John Lamb, leader of Southend Council’s Conservative group, said: “The survey quite rightly showed people are totally against a Thames Estuary airport – and I believe they are right.

“We don’t need a Thames Estuary airport and I will fight it tooth and nail.

“This survey is a true reflection of the opposition in Medway, Kent and Southend.”

Results of the poll, commissioned by Medway Council and Kent County Council, of 2,000 people, came on the final day for people to comment about the plans.

Evidence for and against the estuary airport must be submitted to the Airports Commission, which is looking at how to increase airport capacity in south east England, by today.

Mr Johnson has submitted a report with research from the Civil Aviation Authority, showing one million people will be subjected to harmful noise if a third runway is built at Heathrow.

Southend, Medway and Kent councils have submitted objections to the four-runway plan, which the commission admits would mean the closure of Southend Airport.

Mr Lamb said: “The estuary airport would need to be bigger than Heathrow to cope with the increased traffic.

“That would have an impact on shipping, which is coming up and down the Medway, to Tilbury and DP World ports.

“It will affect the fisheries and the whole ecology of the estuary.”

The commission is expected to publish a report on the estuary airport plan in July and decide whether to include it on the final shortlist, by September.

Its final report, detailing recommendations to Government, is expected in the summer of 2015.