Down in the marshlands of Kent, battle lines are being drawn. In Lydd, a historic gateway town near the headland of Dungeness – a desolate moonscape of gravel dunes, bungalows and tundra – the people are angry.

They are angry at proposals to build more homes on the edge of town at a time when younger inhabitants are moving away. They are angry at plans to develop a series of quarries that will have conveyor belts running all night. And they are angry about the airport.

Local heritage and environmental groups warn that plans to expand Lydd's tiny airport – now used by private jets, cargo planes and Lydd Air, which flies to Le Touquet in France – will dramatically alter the haunting atmosphere of the marshlands, designated an area of outstanding natural beauty.

The RSPB claims pollution and the use of bird-strike controls to protect passenger planes carrying between 200,000 and two million people a year will be devastating for the area's wildlife.

There are concerns, too, that the flight path poses a security risk to Dungeness nuclear power station and a primary school about 600 metres from where the planes would land.

Posters proclaiming "No big jets" are displayed in windows around town. But walk past the houses with their "For Sale" signs, the closed-down ironmongers, the glassless telephone box and the vandalised memorial garden, and it is clear opposition to airport expansion is far from unanimous.

"We really need the airport to be developed," said Jean Jones, who runs the Two Bob Shop on the High Street. "There's no employment here for the youngsters; they're leaving or causing trouble. The bank's closed down and there are fewer shops. People do their shopping in Romney Marsh now. This town is dying."

Shepway council agreed and approved plans to develop the airport, owned by a Saudi businessman, Sheikh Fahad al-Athel, but in the face of opposition the government referred it to the planning inspectorate. The ultimate decision will rest with Eric Pickles, secretary of state for communities and local government.

Those in favour claim Lydd, also known as London Ashford airport, can already take big jets. Two years ago, 23 jumbos bound for Gatwick landed at the airport due to thick fog. In the 1950s the airport, then known as Silver City, flew tens of thousands of passengers and their cars to mainland Europe.

"This would create up to 1,000 jobs," said Jean's husband, Bob, a parish councillor and leading light in the Friends of Lydd Airport Group, who believes that the 200 or so jobs it is claimed would be created at the airport would themselves generate hundreds more. "The whole marsh is dying. This is the most deprived area in southern England. Folkestone and Ashford are getting money, but there is nothing here." But Bob and Jean are optimistic: "In this economic climate it's got to get the go-ahead."

It's a view shared by local Conservative MP Damian Collins, whose blog champions the government's plan for growth, which he claims will bring "radical changes to the planning system to support job creation". Collins knows which way the wind is blowing. The government is determined that "sustainable growth" takes centre stage in the planning process. Its national planning policy framework, unveiled last month, repeatedly confirms that planning must be seen as a tool of economic growth, an emphasis seized on by developers and housing experts.

"It's possibly the most useful thing the coalition government has done," said David Orr, chief executive of the National Housing Federation, which represents England's social housing providers. "For too long the scales have been tipped in favour of those opposed [to development]."

Orr knows the figures better than most. Last year about 100,000 homes were built in Britain, but most experts agree there is a need to build about 250,000 homes a year to cater for the country's burgeoning population.

The government's new framework recognises this shortfall, instructing local authorities to update their five-year house-building plans and to increase their construction targets by 20%. Although only a draft, it is already governing decisions. Planning officers have been told to recognise that it is of "material consideration" when considering applications. Decisions that have been rejected are being reprised as developers anticipate that the coalition's pro-growth development strategy will allow them to override previous objections.

This is the concern of locals in Slad Valley, Gloucestershire – Laurie Lee country – close to where Barratt Homes hopes to build 48 houses, 30% of which will be allocated to affordable housing. Stroud council rejected the plan, but the new framework suggests the development could yet see the green light.

"It's almost certain they will appeal," said Geoffrey Murray, chairman of the Stroud district branch of the Campaign to Protect Rural England (CPRE). "They [the developers] know that the council have got to hit these 20% extra targets."

Crucially, it has been estimated that as few as 5% of councils will have up-to-date development plans by next April when the new framework is due to come into force. This is important. The government has signalled that councils failing to meet the deadline will be assumed to be in favour of a "permissive planning system". Or, as John Howell MP, parliamentary private secretary to Greg Clark, the minister of state for decentralisation, explained in January, developers will be able to build "what they like, where they like and when they like", provided they meet new planning guidelines.

Unsurprisingly, conservation groups have expressed alarm at the "permissive" emphasis, which they believe is driven chiefly by the Treasury. The likes of the National Trust and the CPRE are alarmed that the framework dispenses with guidance stressing development of brownfield sites should come before greenfield, and that it contains no commitment to respect the "intrinsic value" of the countryside. As a result, they warn developers will "cherry-pick" cheaper greenfield sites at the expense of brownfield. Greenery around towns and villages will simply disappear, they say.

But it will not happen without a fight. The National Trust is canvassing its 3.7 million members as it prepares its response. Prominent campaigners, such as comedian Griff Rhys Jones, have joined the fray, warning the new framework will "slash, burn and rampage through current planning laws". There is talk that the escalating row will go the way of the government's attempts to sell off the nation's forests.

So far the government has dismissed the objections, claiming the framework reiterates a commitment to protecting the greenbelt and areas of outstanding natural beauty. Planning minister Bob Neill has gone as far to suggest the objections are the work of a "carefully choreographed smear campaign by leftwingers based in the national headquarters of pressure groups" – a charge rejected by those at whom it was targeted.

"We are not against development," said Shaun Spiers, chief executive of the CPRE, who is critical of Labour for not providing an "adequate response" to the row. "We accept planning needs to be streamlined. But there's no evidence this framework will kickstart the economy. Where is the advantage in introducing the sort of planning system seen in Portugal, Greece and Ireland?"

Orr rejects the concerns: "This will not result in a concreting over of the countryside. Period." But many Tory backbenchers are aware that the row could affect their core support and it is rumoured that the government will seek an NHS-style "listening exercise" in the autumn to try to defuse the situation. The government knows it is not the leftwingers it needs to fear. It is middle England. And it's ready for a fight.

• The following correction was published in the Observer on 28 August 2011:

"Activists prepare for battle to save countryside from the developers" (News) claimed Lydd airport in Kent, "can already take big jets. Two years ago, 23 jumbos bound for Gatwick landed at the airport due to thick fog". Lydd's runway does not have that capability. We meant nearby Manston airport.