A battle over parts of the Green Belt around Redhill and Reigate suggested as sites for hundreds of new homes this week stepped up a gear with Britain’s oldest national conservation body joining objectors.

The Open Spaces Society (OSS) has objected strongly to the proposal in Reigate and Banstead Borough Council’s Core Strategy to demote the special landscape designation of green belt on the west side of Reigate.

The society, along with other objectors such as Save Reigate’s Green Belt and The Reigate Society, has stated it strongly opposes the plan to redesignate the area to the west of Clayhall Lane and Park Lane as Sustainable Urban Extension.

The land is currently designated an Area of Great Landscape Value.

The area of South Park and Woodhatch to the South-west of Reigate, along with land east of Redhill and Merstham, has been put forward by the borough council after a borough-wide review as two “broad areas of search” which could be proposed for Green Belt development in future, for 500 to 700 homes each.

In a statement on its website, the borough council said: “The council, and all of its councillors, is extremely reluctant at taking this step, as it has held a position of not contemplating any development on the Green Belt - apart from minor, exceptional cases - for many years.

“However, the planning inspector has stated that such a position is not acceptable, and that the council’s Core Strategy cannot be approved if this position is maintained.”

The Core Strategy, the council's central planning policy, is essential to the council in that without it being approved, the council would not be able to apply local criteria to future planning applications.

Only the National Planning Policy Framework (NPPF) would apply, which, the council stated, is less strict than its policy.

The council therefore announced last month that after six years of trying to get its Core Strategy approved by a planning inspector, it had been “forced” to propose amendments to the strategy.

Under the amendments, the council said that towards the end of the planning period in 2027, some areas of the Green Belt could be reviewed if, at that time, there had not been enough brownfield land to meet local housing needs.

The Green Belt areas in question are those to the South-west of Reigate and east of Redhill and Merstham.

Public consultation on the amendments closed on Monday (February 4).

But the Open Spaces Society, founded in 1865 to campaign to protect common land, village greens, open spaces and public paths, and people’s right to enjoy them, this week called on the borough council to think again.

Referring to the Reigate site, the society's general secretary, Kate Ashbrook, said: “We have called on the council to remove the proposed area from the Sustainable Urban Extension designation, and to give it permanent protection from development.”

Ms Ashbrook said: “This is an area of immense natural beauty, much enjoyed by walkers and riders.

“It is criss-crossed by public paths, some of them official, others permissive - but all of them popular.” She continued: “The land adjoins Priory Park, an important and valued open space.

“Together these areas provide a green lung and also act as a buffer, places where one can find beauty and tranquillity, increasingly vital in today’s pressured society.”

She added: “Park Lane, a narrow route with great character, cannot accommodate additional traffic which would be generated by any further development here.”

Last week, Crispin Blunt, the MP for Reigate and Redhill, took the Green Belt battle to Parliament, having secured a debate in Westminster Hall with Planning Minister Nicholas Boles.

Mr Blunt put the planning inspectorate in the firing line, having criticised it for “subverting local Green Belt policy” by reviewing the Core Strategy and calling for more analysis of options for development, against the borough council's wishes.

He pressed the planning minister for assurances that interference by the planning inspectorate would not result in the “violation of two central tenets of the Government’s policy of localism, and protection of the green belt.” He also spoke out about his concern that these strategic objectives appeared to be “undermined by how planning policy is delivered in practice”.

However, the Planning Minister replied that localism was “no free lunch,” and did not indicate a resolution for constituencies like Reigate which sit entirely within protected zones.

Speaking afterwards, Mr Blunt said: “I am disappointed that the minister could not make clear which national policy he believes trumps which: the delivery of local autonomy through meeting perceived national housing need, or the protection of the green belt?”

He said: “As I put it to the minister, the Government’s rhetoric implies the Green Belt has priority when these two clash, as they do in Reigate, but this is not backed up by the actions of the planning inspectorate for which he is quasi-judicially responsible.”

Before the debate, Mr Blunt had stressed: “The protection of the Green Belt is, and will remain, my top priority as MP for Reigate, a constituency entirely within London’s metropolitan green belt. “The Government has also made much of its localism agenda, so it is not right that development is foisted upon our community by a central authority because it believes that the council’s plan is not in keeping with prescriptive housing targets.”

He added: “The people who are best placed to respond to any community’s housing or infrastructure needs are its own elected representatives, who are properly enfranchised to judge the merits and demerits of development. “I have absolute confidence in Reigate and Banstead Borough Council to make those judgements locally, which is why I oppose this interference.”

In 2010, Mr Blunt told the annual general meeting of the Federation of Banstead and District Residents Association that he would “die in a ditch to stop new development on Green Belt land.”

This week, Green Party borough councillor for Redhill East, Sarah Finch, welcomed the involvement of the OSS, saying: “We feel it’s unsustainable for Reigate and Banstead to be allowing such a high volume of market housing, and the Green Belt should be very strongly protected, and the fact that the developers feel they can sell is not good reason enough.”

Coun Finch said the close of consultation on the Core Strategy amendments “is not the end of the story.”

Calling the strategy the “big picture,” she said while the planning inspector will now look at the comments prior to a public examination, and then decide on the Core Strategy and amendments later in the spring, “the process of writing the detailed planning, the Development Management Documents, goes on.”