Parish councils have been urged to sign up to an alliance campaigning for a reduction in housing targets which they fear could destroy the countryside around Greater Norwich.

The Norfolk branch of CPRE (Campaign to Protect Rural England) is working with localised campaign groups to galvanise opposition to the Joint Core Strategy (JCS), proposed by the Greater Norwich Development Partnership (GNDP).

The growth blueprint has allocated 37,000 new homes across the Norwich, Broadland and South Norfolk council areas, with the greatest concentration proposed for a northern 'growth triangle' around Rackheath.

The GNDP was forced to revisit its allocations following a successful legal challenge – but following a 'rigorous and thorough reassessment' of other options it maintains the growth triangle is still the most appropriate place for up to 10,000 necessary homes.

But while those consultations continue, CPRE Norfolk is intensifying its calls to reduce the overall housing targets, which it described as 'over-ambitious' and not reflective of actual demand.

Earlier this year, it formed a partnership with some of the community action groups which had formed to battle housing allocations both to the north and south of the city. And now it has urged parish councils within the JCS area to throw their weight behind the campaign by signing up to an 'alliance agreement'.

Caroline Davison, CPRE Norfolk's planning and campaigns manager, said: 'We recognise the need for new housing but have grave concerns over the impact on the countryside of 37,000 new houses by 2026. Ten campaign groups and parish councils have already signed up to the alliance agreement, but we are now asking all parish councils affected by the proposals to join us in our campaign for an immediate review.

'These house building targets are over-ambitious and are not being met. They should be reduced to reflect demand more accurately.'

David Hook, chairman of the planning group at CPRE Norfolk said: 'We're not asking for the destruction of the current JCS and a consequent free-for-all from developers, as has been suggested. Instead we're proposing a reasonable and sensible approach that reviews the evidence properly and focuses on initial development of the least sensitive sites.

'We know that there's mounting concern at parish level about the amount of housing proposed. By joining the alliance, parish councils will send out a message to the local authorities that they're not willing to stand by and watch the destruction of the countryside around Norwich.'

Andrew Proctor, leader of Broadland District Council and chairman of the GNDP, said: 'The growth triangle remains the focus for future growth in Broadland as part of the joint core strategy not just for housing but also for employment sites and valuable green infrastructure. The GNDP partners across Broadland, Norwich and South Norfolk are committed to ensuring that all growth across the whole area will be sustainable and supported by the necessary infrastructure.

'Norfolk's population has grown considerably in recent years as the last census demonstrates. All the latest forecasts show a continuing demand for housing and the proposed levels of growth in the whole joint core strategy through to 2026, of both housing and new jobs, are both reasonable and valid in that context.'

'A rigorous and thorough reassessment of many alternatives for growth has been undertaken supported by legal and independent consultant's advice. It concluded that the most appropriate location for growth remains the north east growth triangle.'

A pre-submission consultation on the re-assessed JCS plans runs from August 10 to October 8.

=Parish councils wishing to sign up to the CPRE's alliance agreement should contact Caroline Davison on 01603 761660 or carolined@cprenorfolk.org.uk.