The Wildlife Trust for Birmingham and the Black Country said it strongly opposes any development of the Seven Cornfields site, near Wolverhampton.
It comes as a campaign was launched last week objecting to proposals for 1,300 homes on the 284-acre site.
The charity highlighted the land’s importance for local wildlife – and has requested it to be given special conservation orders.
Simon Atkinson, head of conservation at the trust, said: “Whilst understanding the need to build new homes, the charity is strongly opposed to any new development that will have significant negative impacts on areas of high ecological value and the wildlife that depends upon them.”
The charity undertook surveys of the Seven Cornfields site – within the Wolverhampton boundary side – in 2018.
It requested that the site’s patches of woodland and hedgerows be given special listings which would declare them as important local sites of nature conservation.
However the requests are still with Wolverhampton Council.
The idea that the green belt, which is regarded as precious land by the local community, could be built upon has caused outrage.
Tony North, who lives in Sedgley, said: “People love green fields and nature, but our objections to this scandalous proposed development are not based on emotion.
“The land is a green wedge and a vital part of a wildlife corridor that stretches from Penn all the way to Sedgley Beacon. It abounds with wildlife, bats, badgers, deer, owls, woodpeckers, masses of other bird life.
“Buzzards regularly patrol overhead. Go on google maps and look towards Walsall from the Beacon and the next green space is miles away.
“Alder Coppice is an ancient oak woodland and has just been given Nature Reserve status. The proposal to build 1300 houses alongside it is ridiculous.” The planning authorities for the land are Wolverhampton and South Staffordshire councils, with Wolverhampton sharing a third of the site.
Local plan review
South Staffordshire said it has not yet considered the site as part of its “local plan review” – which looks at new areas for housing and employment.
However, the council is yet to officially look at any sites, and won’t unveil a list for public consultation until summer 2020.
A document – headlined ‘South Staffordshire Local Plan Review’– was circulated at a public meeting into the proposals last week. It contained proposals, on behalf of Barratt Homes and David Wilson, for how to develop the Seven Cornfields site.
A spokesman for South Staffordshire Council said: “Planning agents acting on behalf of the landowners responded to a consultation that South Staffordshire Council’s local plans team was carrying out in 2018 – as part of an earlier stage of our local plan review.
“In addition to commenting on the issues facing South Staffordshire, the agent took the opportunity to promote this area of land and included details of how they saw the land being developed.
“The land had also been suggested to City of Wolverhampton Council as being available for development.
"Neither South Staffordshire Council, nor the (West Midlands) Combined Authority, has endorsed the site, however, it would appear the representation made by the agents has been incorrectly interpreted as being given the go-ahead.
"To be clear, the site does not form part of our local plan review. At this stage of our local plan review, no sites have been selected.”
A Barratt Homes source said the document was a "premature version which was put into the mix".
Wolverhampton South East MP Pat McFadden, who met with a regional director of Barratt Homes on Friday, said: "Barratt Homes have entered a partnership with the landowner to develop a proposal to build new housing on the site.
"The initial focus must be to stop this green belt land being released for housing development."