In a joint statement, the ODPM and DEFRA said the policy will remain in place. It allows councils to grant planning permission for affordable homes on small sites that local plans might not otherwise release for housing.
The ODPM consulted in the summer on plans to replace the policy with one that enables sites to be allocated solely for affordable housing.
Planning authorities have supported the policy but want to keep rural exceptions, so both policies will be incorporated into PPG3.
"We have listened to councils and the rural communities who told us that we should keep the exceptions policy," said planning minister Keith Hill.
A Campaign to Protect Rural England spokesman said: "We see the need for more affordable housing but there should not be a special category for greenfield growth."