DAVID Cameron today acknowledged the need for more airport capacity in the South East and said ministers would study the case for a new airport in the Thames estuary.

The Prime Minister insisted the UK must not give up its status as a major global hub for air travel, although he acknowledged the issue was “controversial”.

In a speech setting out his long-term “vision” for British infrastructure, which also included the announcement of moves to attract private investment into the UK’s roads, he said the coalition’s aviation strategy would include “an examination of the pros and cons” of a new Thames estuary airport.

“I’m not blind to the need to increase airport capacity, particularly in the South East,” he said. “We are acting now to make the best use of existing capacity - Gatwick is emerging as a business airport for London, under a new owner competing with Heathrow.

“But we need to retain our status as a key global hub for air travel, not just a feeder route to bigger airports elsewhere, in Frankfurt, Amsterdam or Dubai.

“Yes, this will be controversial. We will need to take decisions for the long-term - and we will be bringing forward options in our aviation strategy which will include an examination of the pros and cons of a new airport in the Thames estuary.”

Mr Cameron said the transport challenges facing the country were “clear”. “Demand for rail is higher than at any point since the Second World War. Our roads are congested, our key hub airport is full, by 2030 the distance travelled by road and rail in the UK is expected to increase by at least a third.

“Without world class transport we will not get growth, people won’t invest here and regions in decline will be further left behind. Without better transport, we will continue to pollute, too.”

Mr Cameron said the country needed to be “more ambitious” about improvements to its road network.

“We need to look urgently at the options for getting large-scale private investment into the national roads network - from sovereign wealth funds, pension funds, and other investors,” he said.

“That’s why I have asked the Department for Transport and the Treasury to carry out a feasibility study of new ownership and financing models for the national roads system and to report progress to me in the Autumn.

“Let me be clear: this is not about mass tolling - and as I’ve said, we’re not tolling existing roads - it’s about getting more out of the money that motorists already pay.”

The Prime Minister warned there had been a “failure of nerve” in the past which he was determined to overcome.

“We will take difficult decisions, we will risk short-term unpopularity, and we will hold fast to our vision in the face of vested interests, because our motivation and our duty is to protect and champion the national interest.”

In a speech at the Institution of Civil Engineers, the Prime Minister admitted there would be “furious objections” to his proposals.

“There will be costs and protests. And I am certainly not doing it in the hope of immediate political advantage,” he said.

“I can see the furious objections - the banner headlines - already. But rather than give in we should ask instead ‘What is it that people want for the future?’

“Reasonable things - a decent home, a clean environment, jobs for their children, the ability to get around without hassle, huge costs or endless jams.

“And then we should take the necessary steps to make these things a reality, not leave future generations to deal with the consequences of our cowardice.”

Tory Mayor of London Boris Johnson has been a leading exponent of a new airport, dubbed the “Boris Island”, on reclaimed land in the Thames Estuary.

Architect Lord Foster has also produced plans for a �50 billion airport on the Isle of Grain in Kent, also involving some land reclamation..

The Government announced in January it would be looking at the ideas as part of an aviation consultation starting this month.

In answer to journalists’ questions today, Mr Cameron said: “We should examine the case for an estuary airport. It’s important to have an open mind on these issues.”

Asked if he was “warming” to Mr Johnson’s idea, Mr Cameron said: “I have always thought that it is worth examining the potential for these ideas. Government should have an open mind, should be enquiring.

“The aviation paper that we will be producing will look at a range of options and possibilities, scope the whole issue but also look at what the estuary options are - obviously there (is) more than one.”