The lobby group commissioned a survey of senior planners at local authorities to investigate their views on what would happen in their areas if the proposals became policy. Planners reported that they would face increased pressure to guarantee a supply of land, which could make it difficult to prioritise brownfield sites. They did not believe that the policy change would make any detectable difference to house prices.
The CPRE also analysed 24 industry body and voluntary sector responses to the government's planning for housing consultation. It found widespread concern that the proposals would undermine urban regeneration, worsen regional disparities and fail to tackle the lack of affordable housing.
Speaking at a housing conference this week, CPRE chief executive Shaun Spiers said: "The government should promote homeownership among people who do not have enough of it, while demoting it among those who have an abundance of it."
But a Home Builders Federation spokesman attacked the CPRE's findings.
"I just don't think this is correct. The government's proposals have been misunderstood," he said.
"If local authorities want housing on brownfield land, they can help ensure that there is enough of it. For example, they can bring forward land designated for employment that has not been used. If the current system is so good, why isn't it delivering?"
RTPI policy officer Chris Scrafton said that the institute agrees with the pitfalls of the government's land release proposals highlighted by the report. "What this report does show is the increasing pressures on land and especially the green belt," he added.
"It is time for an intelligent and informed debate on how we use green belt land. By blindly sticking to current policy rather than allowing debate and discussion we are in danger of losing out on creating integrated sustainable developments and preserving our green spaces."