Just one in six of the homes being developed in the east of England, a housing hotspot, is affordable, according to figures released by the regional assembly.
It also notes that only 4,042 affordable properties were built between 2005 and 2006, 63% short of the target of 11,000. Overall 24,500 homes were built in the region during this time.
The east of England, which includes the counties of Cambridgeshire, Suffolk, Hertfordshire, Essex, Bedfordshire and Norfolk has an average house price of more than £200,000.
The figures are contained in the housing investment plan of the East of England regional assembly, which calls for a substantial increase in grants to build subsidised housing for people who cannot afford to rent or buy on the open market.
The plan, which outlines how money for affordable homes in the region should be spent between 2008 and 2011, has been sent to Yvette Cooper, the housing minister.
The assembly has called on the government to make at least 35% of all new housing in the region affordable.