A Thames Estuary airport could be ruled out by the end of next year.

Sir Howard Davies, who is leading a commission investigating airport capacity in the UK, said an interim report due by the end of 2013 will narrow down the options.

As well as an airport in Kent, other proposals include building a third runway at Heathrow, a second runway at Gatwick or expanding Stansted.

The government set up the commission in September in an attempt to solve what has long been a contentious issue.

The commission got to work today (Friday) and Sir Howard said his aim was to provide the government with a “flying start” in its final report due after the next election in 2015.

He pledged in an interview with the BBC that it would be a “really expert piece of work looking at how we think about airport capacity, which I hope will be internationally leading-edge.”

Sir Howard added that although the commission couldn’t put forward final recommendations for a number of years, it could carry out preparatory work.

This would include environmental and noise assessments, as well as the business cases for the various plans.

The idea of an airport in the Thames Estuary has been put forward countless times in the last 70 years, and one of the key arguments against the proposal is that it would cause untold environmental damage.

Cliffe, Grain and two floating islands in the estuary itself have been proposed as sites in the last four years.

The floating airport option has been championed by London mayor Boris Johnson, who has attacked the government for putting off a decision on the issue.

Mr Johnson said today this represented a “policy of utter inertia”.