The Education Minister, Charles Clarke, announced measures on Monday intended to "stem the loss of playing fields" used by schools.

"School playing fields are an invaluable resource and one to which this government attaches the highest priority. As well as providing an outdoor classroom, they add to local people's quality of life. Their loss almost always causes widespread concern," said Mr Clarke.

Charles Clarke wants to place tight restrictions on sales of playing fields

Pressure on budgets had led many schools and local authorities in the 80s and 90s to sell playing fields for housing or commercial development, creating fears that children would be deprived of sports grounds and space to play outdoors.

The government's "tough new guidance" on playing fields will impose tighter restrictions on the sale and development of playing fields.

Sales will be allowed only if the proceeds are put back into sports provision, there are sufficient alternative facilities for both the school and local community, and local people have been consulted.

The restrictions follow an earlier clampdown - under legislation passed last year - in which schools or councils wanting to sell playing fields had to seek the permission of the Department for Education.

The government estimates that in 1997 sales of school playing fields were running at 40 a month, and says applications are now down to about a dozen a month. Critics of the government's policy have said that applications tend to be approved, however.