Regional planners are “burying their heads in the sand” over plans to build 365,000 houses over the next 20 years, countryside campaigners have claimed.

The Campaign to Protect Rural England claimed the Government was actually planning up to 490,000 new homes in the West Midlands.

And it accused the West Midlands Regional Assembly - the regional planning body, which includes councillors and business leaders - of failing to stand up to Ministers.

Proposals for 365,000 new homes over the next 20 years were included in the Regional Spatial Strategy, a masterplan for the region’s future.

However, the CPRE has discovered that consultants Nathaniel Lichfield and Partners have been asked by the Government to examine whether this could be increased to 460,000.

According to the CPRE, planned housebuilding could lead to the loss of green-belt land near Coventry, Birmingham, Solihull, Cannock Chase, Lichfield, South Staffordshire, Nuneaton and Bedworth, Stratford-upon Avon, Warwick, Bromsgrove and Redditch.

It has written to David Smith, Chairman of the West Midlands Regional Assembly, to demand a full-scale review of the green belt.

Peter Langley, Chairman of CPRE West Midlands, said: “The Regional Assembly should own up to the impact of their housing strategy on existing green belt and look at adding green belt where necessary. They need to take a robust line with the Government over its housing proposals.

“Green belts control and channel development into areas where it does the least damage to the countryside and the environment. A strong green belt, fit for the challenges of the twenty-first century, is vital to support efforts to breathe new life into our towns and cities. Without it, the planning strategy simply isn’t complete.”

Olwen Dutton, Chief Executive of the Regional Assembly, said: “CPRE are well aware that the Assembly stands very firmly behind the principles of the green belt.

“However, in developing the strategy in liaison with our partner authorities across the Region, it became clear that in a limited number of cases, it would be sensible to allow for some small local adjustment of greenbelt boundaries if housing needs are to be met in the most sustainable way.”

Most new development would take place on land which was already developed, in high population areas, he said. The Regional Assembly plans to focus as much development as possible on brownfield sites, particularly in the region’s major urban areas of Birmingham, the Black Country, Coventry and the north Staffordshire conurbation, the agency said in a statement.