Increased development on greenfield sites will be necessary to accommodate them, despite the Government's wish to cut back on greenfield building, and new towns will also have to be considered. Some south-eastern counties whose countryside is already under heavy pressure, such as Berkshire and Buckinghamshire, will face an increase of more than 60 per cent in their planned levels of building.
"This will have a devastating effect on the countryside of the South- east, which is already facing ferocious development pressures," Tony Burton, assistant director of the Council for the Protection of Rural England (CPRE), said yesterday.
"Since the end of the Second World War, an area of countryside bigger than Greater London has already been built over in the South-east. Two- thirds of the region is already disturbed by the impact of development and traffic. This can only bring further environmental misery to Britain's most pressurised region.
"If development continues at this rate, a third of the South-east will be under concrete by 2050."
The proposals are at the heart of the draft regional planning guidance for 1991-2016 which is being finalised today by Serplan, the planning conference of local councils in the South-east outside London, and which has been seen by The Independent.
The main proposal is for 862,000 new houses to be built in the region over the period, which would mean an extra 267,000 new homes after 2006. The planners are proposing that a further 52,000 houses should be built if the need arises, which would take the new total to 319,00 - the equivalent of a city the size of Leeds.
A number of areas are identified by the CPRE as being at particular risk, including the large bands of open countryside between Reading and Basingstoke, and between Basingstoke and Winchester. It thinks the planners are pencilling in at least 100,000 houses more than will be necessary.
Serplan, however, is planning for fewer homes than the Government's household projections for the period - which are for 1,104,000 new households to be formed.
In February the Secretary of State for the Environment, John Prescott, said the Government would abandon the "predict and provide" approach which was based on building houses to accommodate the projections.
Today the House Builders Federation attacks Serplan for its proposed reduction, saying: "Councillors plan to deny at least a quarter of a million households in the South-east a decent home of their own. This will lead to increased price inflation and cause huge demands for council housing which the Treasury is unable to fund."