Is the world ready for 'Boris island'?

The Government is poised to re-open the vexed and controversial debate over the expansion of air travel in South-east England after confirming plans to hold a consultation on a new airport in the Thames Estuary.

In a move which will pit businesses against local residents and environmentalists for years, ministers will include the option for a new London air hub in a consultation on UK aviation this spring.

David Cameron and George Osborne are thought to have warmed to the idea, first proposed by the London mayor Boris Johnson as a way to boost the economy and increase long-term investment in the UK.

But any move to build a new airport in the South-east will be bitterly opposed by environmental groups, who believed they had won the battle against air expansion when the Coalition ruled out building a third runway at Heathrow.

Friends of the Earth's executive director, Andy Atkins, said a new airport would have a "devastating impact on local communities and the environment. "London doesn't need another hub airport – the capital already has more flights to the world's main business destinations than our European neighbours. David Cameron's pledge to lead the greenest Government ever will ring hollow if he gives the green light to a huge expansion in air travel."

The architect Lord Foster has already produced plans for a £50 billion airport on the Isle of Grain in Kent, which has been backed by Mr Johnson.

The plan envisages a 24-hour, four-runway airport, with each runway 2.5 miles long and with facilities to cope with 150 million passengers a year.

The scheme is backed by business groups and the airline industry. Simon Buck, chief executive of the British Air Transport Association, said: "The Government needs to maintain and build UK connectivity to emerging markets through permitting privately funded additional extra airport capacity where it is most needed and demand is greatest – in the South-east. Without this, the competitiveness of the UK economy will continue to be eroded."

But Protect Kent, which promotes the diversity of rural England, argued that the airport would have a disastrous impact on land both north and south of the Thames. Leaders on Medway Council called on the Transport Secretary, Justine Greening, to attend a meeting and hear their objections to the scheme. In an open letter, the council's four group leaders said that 76 per cent of the UK public are opposed to the airport.

"It would have a huge affect on the lives of hundreds of thousands of residents in Medway, as well as across Kent and the wider Thames estuary, and would devastate an area of global environmental significance. An airport would cost up to £70 billion, would require huge highways and infrastructure and would cut great swathes off the green belt and countryside," the Council's leaders say.

But Mr Johnson himself said he believed the tide of opinion was changing in favour of a new airport: "I think that where we are is that the Government is increasingly interested in this idea. I genuinely believe that they see not just the overwhelming aviation argument and the argument from international competitiveness in making sure that Britain has a hub airport that is viable for the long-term future. I also think the Government understands the massive regeneration potential of this project.

"You can't go on expecting Britain to compete with France and Germany and other European countries when we simply can't supply the flights to these growth destinations – China, Latin America. We are now being left badly behind."

Downing Street said that the Government had made clear in last November's Autumn Statement that it was ready to "explore all the options for maintaining the UK's aviation hub status, with the exception of a third runway at Heathrow". A spokeswoman added: "We will be consulting on the sustainable framework for UK aviation this spring."