Most councillors in green-belt areas believe that the land will be given over to housing in the next five years.
A survey for the National Trust found that 58 per cent of councillors agreed the land would be lost, compared with 51 per cent of those asked the same question in 2013.
The responses to the Local Government Information Unit (LGiU) survey came just before the government publishes its housing white paper. Nearly three quarters of local councillors believe that the planning system favours developers while just over half said that housing was being approved even if they were not in line with local plans, because of relaxed regulations.
The LGiU warned that many councillors felt that the democratic tool of having to approve applications at a council level was being undermined and power was being skewed towards developers and the government. It voiced concerns that the National Planning Policy Framework, introduced in 2012, was failing to put communities first.
Almost half of respondents had seen an increase in the number of planning decisions being challenged and overturned since the framework was adopted. Of those respondents, half said that it made councils more likely to approve schemes.
Less than a fifth believed that the framework had improved design quality and half of the 1,278 councillors surveyed thought that their planning departments were not adequately resourced.
Jonathan Carr-West, LGiU chief executive, said: “The planning system is one of the fundamental pillars of local democracy, allowing communities to help shape the physical structure of the places they live. Councillors are the most important link between communities and the system. Our survey with the National Trust shows that many councillors feel that this democratic tool is at risk of being undermined.”
Ingrid Samuel, historic environment director at the trust, said: “It is almost five years after the government’s planning framework was adopted, so it’s worrying that councillors feel it hasn’t delivered the localism promised.”
Sajid Javid, the communities secretary, is due to launch the white paper this month. There is tension within the Conservative Party between the need to build more houses and fears over a “backlash” from middle England.