Residents and groups have said they will do all they can to defend an area of open land near Chichester which has been earmarked for up to 100 homes.
Initial proposals to build on the rural land between Chichester and Lavant, known as ‘the daffodil fields’, were fiercely opposed when they were presented to the city council last week.
Now The South Downs Society and CPRE Sussex Countryside Trust have joined residents in criticising the plans, put forward by Taylor Wimpey.
Jeremy Hunt, chairman of the Summersdale Residents’ Association, said: “Residents are almost, without exception, against any encroachment on this strategic gap. This land is one of the smaller strategic gaps but it needs defending.
“This development would be highly visible and the national park boundary runs along the side of this site.”
Mr Hunt said a new Residents Against Greenfield Encroachment group (RAGE2) has been formed to oppose the plans. This consists of residents and councillors from the Chichester and Lavant areas.
National park campaign group the South Downs Society said the development would mean the loss of a quarter of the unspoilt countryside between the two areas.
“It’s no wonder that local residents are up in arms,” said South Downs Society’s policy officer, Steve Ankers. “Heading out of Chichester, the new housing estate would dominate the first dramatic view of the national park.
“It would also spoil views from the chalk escarpment, at the Trundle and Seven Points, looking down across the coastal plain and the cathedral.”
Chairman of CPRE Sussex, Rodney Chambers, said: “This attempt to extend urbanisation into our precious countryside would place further strain on our already over-stretched local roads and services.”
A spokesman on behalf of Taylor Wimpey Southern Counties, said: “As part of the preparation for our planning application we will be carrying out a full landscape assessment to identify whether our proposed development has an impact on the national park.”