Campaigners have raised concerns about government proposals to open up the green belt for development as part of plans to build hundreds of thousands of new homes.
Prime Minister David Cameron unveiled a major expansion of the shared-ownership scheme to boost home ownership in England.
But details of a consultation on national planning reforms later emerged that show the Government wants to ease restrictions to allow "appropriate small-scale sites in the Green Belt specifically for starter homes".
The Campaign to Protect Rural England (CPRE) warned that the changes would make housing problems worse.
Paul Miner, the CPRE's planning campaign manager, told the Daily Telegraph: "The current policy isn't working, but these proposals will make things worse. It could see a lot more planning battles in the countryside over coming years."
Clive Betts, chairman of the Commons Communities and Local Government committee, told the Telegraph the consultation was "very worrying".
He said: "I have no problem with a proper review of the Green Belt to see whether it is all appropriate or whether more should be added in. But that is how it should be done, not as a bit of an opportunity to cherry pick the best sites by developers, which this sounds like it could develop into."
The Government has pledged to create 400,000 properties as part of the largest affordable housebuilding programme in more than 30 years.
Mr Cameron announced in a speech in Staffordshire that rules preventing people from using the shared-ownership scheme - which allows people in England to part-buy, part-rent properties, increasing their share of the ownership over time - more than once will be abolished.
The change will free up people to move from one shared-ownership property to another - allowing them to use the capital they accrue to trade up to a bigger home as their families grow or their circumstances change.