Figures published today show that the total number of primary and secondary schools in that category rose from 243 to 256, an increase of just over 5 per cent. Thirty-five schools were removed from the category.

Ofsted introduced a new lighter-touch inspection regime in September 2005 that includes shorter inspections and more emphasis on school self-evaluation. At that time, inspectors said they were “raising the bar”

of the standards schools needed to meet.

The rise in the number of schools in special measures follows a sharp jump during the autumn term last year when the figure increased by almost 17 per cent. During that period, primaries were performing considerably worse than secondaries, with an increase of 25 per cent. That slowed last term to a rise of 4 per cent.

The number of schools given a “notice to improve” - those which inspectors say are inadequate but have the capacity to improve- fell from 366 to 352.

Steve Sinnott, general secretary of the National Union of Teachers, said:

“Ofsted changed their criteria so it is inevitable that more schools will be put in special measures.

“It is not a fair system. The goalposts have moved but the terms and condemnation remain. Light-touch inspections focus on English, maths and science and are not concerned with the whole range of good work going on in schools.”

Jim Knight, the schools minister, said it was significant that, overall, there were fewer schools in categories of concern. “The new, tougher inspection framework means there is no room for coasting schools,” he said.