Plans to build more than a million homes in England to halt the rise in house prices would have devastating environmental consequences, an unpublished government study is reported to have concluded.

Party Response: Conservative

Caroline Spelman, shadow local and devolved government secretary, said: "This report highlights the devastating consequences that the government's plans to concrete over our green fields would have.

"We call upon the government to reject the Barker report and also to re-think John Prescott's Communities Plan."

Forum Response: Construction Products Association

Allan Wilén, economics director at the Construction Products Association, said: "The environmental repercussions reported by the Daily Telegraph appear very wide of the mark.

"The 1.4 million extra new homes proposed by Kate Barker will add only seven per cent to the existing housing stock and as a minimum they will be built to the high environmental standards demanded by current building regulations and will accordingly be far more energy efficient than the average existing home.

"Furthermore, with building standards under revision in 2005 and 2010 to ensure the highest level of energy efficiency, CO2 emissions in new building stock will not be anywhere near the level quoted in the article.