Inspectors say almost half of schools they visited are not providing their pupils with a good education, statistics reveal today.
Some 47% of the 3,990 schools inspected between September and March 2009-10 were judged to be either inadequate or satisfactory. Ofsted inspectors rated 9% of schools in England as inadequate, compared to just 6% in the academic year 2006-07, the figures show.
The proportion of schools labelled outstanding – the highest rating – fell to 11% from 14% in 2006-07.
Lord Hill, the schools minister, called for urgent reform to reduce the number of schools that are under-performing.
But teachers warned that today's figures could not be compared with previous years because inspections had become much tougher since a new inspection regime was introduced last autumn. Inspectors are also visiting more schools that are "of concern" than in previous years.
Some 5% of schools were given "notice to improve", while 4% were placed in the worst category – special measures – which means they risk being closed down.
Hill said there was an "urgent need for real reform".
"We need to create more excellent schools and drive up standards across the board – and that's exactly what our academy proposals will help to do," he said. The government plans to continue to make inspectors concentrate on the weakest schools, leaving the best ones free from any inspection.
Mary Bousted, general secretary of the Association of Teachers and Lecturers, said the inspection regime placed "huge pressure on schools not judged good or outstanding to teach to a narrow curriculum that won't necessarily develop the skills, attitudes, confidence, and passion for learning which young people need".
Chris Keates, general secretary of the Nasuwt union, said it was impossible to draw any meaningful comparisons between the proportion of schools judged good or outstanding today, and the number in previous years.
She said: "Ofsted accepts that disproportionately more of its time is spent inspecting particular categories of schools. The statistics published today are, therefore, heavily biased and do not present a true picture about how well the system as a whole is doing."
Christine Gilbert, Ofsted's chief inspector, said inspectors were looking more at whether pupils made good progress than a school's overall exam results.