Mr Cameron and Chancellor George Osborne are desperate to reform planning rules to provide a boost to the economy.
They claim that current planning rules are holding back firms from expanding, and restricting house-building, keeping prices artificially high.
The draft National Planning Policy Framework (NPPF) distils 1,300 pages of planning guidance into as few as 52 and writes into planning rules a new “presumption in favour of sustainable development”.
However Joan Walley MP, who chairs the committee, said the current draft “appears contradictory and confusing”.
She said: “It pays lip service to sustainable development without providing a clear definition, potentially leaving future planning decisions open to legal challenges.”
The committee called for this presumption to be defined more clearly so it balanced “economic, social and environmental aspects” of development.
Planners in local authorities needed “an NPPF which does not push them to regard the economic dimension as predominant”, she said.
In her letter to Mr Cameron, Mrs Walley said the Government should write into the rules a definition of what is meant by sustainable development.
Mrs Walley also told the Prime Minister that the rules had to include stronger environmental protections.
She said: “The committee considers that the final version will have to make it clearer that the drive for economic growth does not trump other sustainability requirements.”
The framework says developments should be given the green light in communities where local plans are “absent, silent or indeterminate”, leading to fears that they will be sitting ducks for developers’ bulldozers.
Mrs Walley pressed Mr Cameron to delay the introduction of the framework to give people time to draw up local plans which set out where development can take place.
The committee’s report also called for the Government to emphasise that building should take place on brownfield sites before greenfield areas.
Fiona Reynolds, director-general of the National Trust, said the report was a “welcome and important intervention from MPs”.
She said: “If agreed, their recommendations would go some way to helping address some of the key concerns contained within the planning changes.
“It’s vital that a short-term response to the economic situation doesn’t overtake the need for a strong planning system which delivers benefits to communities and the environment as well as the economy.
“The Government must resist any temptation to use the current eurozone crisis as a smokescreen for deregulation, which could cause lasting damage to town and countryside for generations to come.”
A Department for Communities and Local Government spokesman said: “The planning system has always enshrined the principle that the economic, environmental and social dimensions of sustainable development should be considered in a balanced way – and it will continue to do so.
“The framework also aims to strengthen local decision-making and reinforce the importance of local plans. It was always our intention to ensure that appropriate transitional arrangements are in place before the new framework comes into force.”
In a highly critical report, members of the House of Commons Environmental Audit Committee backed concerns by the National Trust and the Campaign to Protect Rural England (CPRE) that the changes could prompt a rash of unsustainable building across the country.
More than 200,000 people have signed a petition by the National Trust opposing the reforms in the National Planning Policy Framework, and there is unease among Conservative backbenchers over the extent of opposition to the plans from their constituents.
The committee has now written to David Cameron urging him to reconsider the “unsatisfactory” wording of the framework and provide a clear definition of what “sustainable” development is to local authorities.
“It just seems to us that, as it’s written at the moment, the planning framework will create a free-for-all,” said Joan Walley, chair of the committee. “It’s a bit like playing football without having the rules of the FA.”
The committee’s report is a setback for ministers, who have been subject to sustained criticism from environmental groups over their proposed changes to planning regulations.
Today’s report comes as a study by the CPRE suggested that there was sufficient brownfield land to build 1.5 million new homes – equivalent to about six years’ supply of housing – without the need to use green sites.
But ministers reject this and argue that simplifying planning rules will encourage growth and reduce bureaucracy, while still ensuring important safeguards against unsustainable development.
Today’s report from a Conservative-dominated committee, including Zac Goldsmith and Caroline Nokes, warns that unless more is done to safeguard the natural environment local authorities will be able to override local opposition with the presumption in favour of development.
In particular, it suggests that it could lead to urban sprawl as towns increase in size, less protection for green-belt land and the loss of previous rules designed to strengthen town centres.
“As it currently stands, the new planning policy framework appears contradictory and confusing,” said Ms Walley. “It pays lip-service to sustainable development without providing a clear definition, potentially leaving future planning decisions open to legal challenges.
“If it protects our greenbelt and countryside, as the Government claims, then there should be no problem in defining sustainable development more clearly to avoid misinterpretation.”
Fiona Reynolds, director-general of the National Trust, welcomed the MPs’ intervention. “Radical changes are needed throughout the draft planning changes if its fundamental flaws are to be addressed,” she said. “It’s vital that a short-term response to the economic situation doesn’t overtake the need for a strong planning system, which delivers benefits to communities, the environment and the economy.”