Figures obtained by the Telegraph have revealed a 60% rise in development on green belt land.
Between 1998 and 2003, the average number of houses built on Green Belt land rose to 5,265 compared with 3,287 from 1994 to 1996, the last three years of Conservative government.
Caroline Spelman, Tory local government spokeswoman, told the paper: "Under John Prescott's watch, Green Belt protection has become worthless.
"The Green Belt has served England well for half a century but this is decreasingly the case. The new figures confirm that it faces a sustained assault from Mr Prescott's army of bulldozers and concrete mixers."
Norman Baker, the Liberal Democrat environment spokesman, said;
"They are redesignating land as Green Belt simply to fiddle the figures,"
The Green Belt is being manipulated by allowing construction near to urban areas, while banning it on land further out that was not at risk.
The Office of the Deputy Prime Minister rejected the criticisms, saying that Labour had increased housing density from 25 to 40 homes per hectare, "making the same amount of land go further".
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