Controversial government plans to build three million homes should be abandoned because of the economic downturn, a committee of MPs says.

A report by the cross-party environmental audit committee says that continuing with the target in the recession would place greenfield land under threat as developers strive to build on it in in preference to ‘brownfield’ land - that is, previously developed sites.

The call for the three million target set by Gordon Brown to be revised has been welcomed by the Kent branch of the Council for the Protection of Rural England (CPRE).

Director Dr Hilary Newport said it was "unrealistic and arbitrary" and would lead to greenfield sites being needlessly sacrificed.

Tim Yeo MP, the chairman of the committee, said: "These ambitious targets were agreed in a time of economic optimism and easy credit. Clearly the assumptions on which they were based must be reviewed in the current climate.

"This is an opportunity for the Government to place environmental concerns at the heart both of targets and planning regulations for new housing."

He added: "Once greenfield land is released for development, this land will be lost for ever."

Dr Newport said: "This report sends an important message. The construction industry is really on its knees and these targets are unsustainable.

"The evidence has been mounting for some time that the three million target is just arbitrary and unrealistic."

The MPs’ call follows figures from housebuilders indicating the scale of the slump.

According to the National House Builders Council (NHBC), there were just 66 applications for new-build starts in Kent from developers in September compared with 604 in September 2007 - a drop of 89 per cent.

Housing minister Margaret Beckett said the Government had no intention of watering down its targets. "Now is not the time to scale back on long-term ambitions because of economic difficulties."