The National Trust today voiced "grave concerns" over Government proposals aimed at dramatically simplifying the planning system, warning of "damaging development" not seen since the 1930s.
Ministers said they wanted to slash 1,000 pages of policy to just 52, while continuing to protect the green belt and areas of natural or scientific beauty.
But the National Trust said the proposed changes could lead to "unchecked" development in the countryside because of a core presumption that the default to any proposed development would be "yes".
The town and country planning system had served the country well, enabling growth, while protecting open countryside and preventing sprawl, said the trust.
Fiona Reynolds, the trust's director general, said: "Those planning principles remain as necessary today as when they were first established.
"Weakening protection now risks a return to the threat of sprawl and uncontrolled development that so dominated public debate in the 1930s.
"The National Trust believes in growth as we all do - but not at any cost. Development that works must pass a triple bottom line test, by showing that it meets the needs of people and the environment as well as the economy.
"Despite some warm words to this effect, the document makes it clear that development is to be encouraged, even urging local authorities to promote more development than is in the plan and over-allocate land for housing.
"The Government's proposals allow financial considerations to dominate, and with this comes huge risk to our countryside, historic environment and the precious local places that people value."
Business groups welcomed the Government's proposals, saying they would help boost economic growth and create jobs.