The government has come under fire after figures revealed that the number of dwellings built on green-belt land in England had risen.

Housing minister Yvette Cooper told parliament that 5521 homes had been built on green-belt land in 2003, compared with 4804 homes in 2002 and 5399 in 2001.

The figures for the years since Labour took office in 1997 were 5691 in 2000, 4910 in 1998 and 4456 in 1997.

Cooper disclosed the information in response to questions from Caroline Spelman, the Conservative local government spokesperson.

Spelman said the statistics showed Labour’s disregard for green-belt planning policies, and that the zone had ceased to provide protection from development.

She accused deputy prime minister John Prescott of overseeing a “sustained assault” on green-belt land with an “army of bulldozers and concrete mixers”.

Cooper noted in her parliamentary statement that the figures for 1997-2000 “reflected planning policies and decisions made before this government took office”.

Norman Baker, the Liberal Democrat environment spokesperson, joined the argument by accusing the government of expanding the fringes of urban areas and changing the boundaries of designated green-belt land to include land that was never likely to be built on.

The 5521 homes built on designated green-belt land in 2003, the most recent year for which figures were available, represented 3% of all new dwellings in the year.