Lord Foster's vision for a Thames Estuary airport

Deputy Prime Minister Nick Clegg has said he is "totally unpersuaded" of the need to build an airport in the Thames Estuary.

In comments that will be welcomed by Kent sceptics of the plans, the Lib Dem leader said "we should take a common sense, hard-headed look at the facts".

Mr Clegg, pictured below, added: "I don't think we should, as a country, decide to concrete over vast swathes of the Thames Estuary on a whim."

His views come just days after it emerged Prime Minister David Cameron is set to announce preliminary backing for a huge airport potentially off the Kent coast.

It follows plans put forward by both London Mayor Boris Johnson and world-renowned architect Lord Foster for airports on different sites around Kent.

Mr Clegg said he would be happy to look at the results of a wide-ranging consultation on UK aviation, due to begin in March, but sounded sceptical about the Thames Estuary plan.

Speaking on the Andrew Marr show on BBC 1 yesterday, he said: "As it happens, if you look at the facts we have four big airports around London, three of which aren't even being used to capacity yet.

"Call me old-fashioned, but it seems like you should first look at things like that."

Mr Cameron's announcement would have been linked in with the High Speed 2 rail announcement, but was put back because it was claimed by Deputy Prime Minister Nick Clegg it was 'being rushed through', according to a nationl newspaper.

Now it is believed the scheme will be unveiled in March, with the Prime Minister broadly backing the plans dependent on consultation.

Medway Council leader Cllr Rodney Chambers said last week he wants to work with the Towns' MPs to secure a crisis meeting with Mr Cameron or Chancellor George Osborne.

He said: "I've no doubt that those affected by this will be ready to fight against this proposal as they did 10 years ago. If there's going to be a battle then so be it."

London Mayor Boris Johnson wants to build a floating airport in the Thames Estuary - dubbed Boris Island.

And plans were announced in November by renowned architect Lord Foster for a massive hub airport off the Hoo Peninsula, taking 150m passengers each year.

The scheme involves building the 24-hour hub airport - with twice the capacity of Heathrow - together with a huge barrage and a new rail network system: effectively an M25 for the railways, skirting London.