Chief inspector Chris Woodhead this week produced his most optimistic report in five years, but warned that the Government's drive to raise standards is at a critical stage.
The annual analysis of the state of schools from Mr Woodhead shows a dramatic improvement in the standard of lessons over the past few years. But it does also suggest that the chief inspector's controversial claim of 15,000 weak teachers could be well-founded.
In presenting its findings, Mr Woodhead stressed the progress that has been made. He said: "Teachers are now teaching better, and pupils, as a consequence, are learning more," he said. "The culture is now less self-indulgent."
In primary schools, inspectors found only 8 per cent of lessons to be unsatisfactory, compared with between 25 and 30 per cent five years ago when OFSTED inspections were first introduced.
The improvement in secondary schools has been only slightly less substantial, with the proportion of unsatisfactory lessons almost halving to between 7 and 10 per cent.
"Teaching is now deemed to be good in over half of the lessons observed in each key stage. More headteachers are monitoring the quality of teaching in their schools. More pupils are as a consequence achieving their potential," said Mr Woodhead.
The chief inspector said the Government's targets for literacy and numeracy in primary schools were achievable, but a great deal depended on improvements in teaching of the basics. "There is no magic wand," he said.
However, while most heads were found to be doing a reasonable job, the data suggest 2,800 schools suffer from poor leadership. The report identifies one in eight primaries and one in seven secondaries as having weak headteachers.
"These are disturbing figures. Too many headteachers do not really know what is happening in the classrooms in their schools," he said.
The proportion of weak heads running secondaries has increased compared to the previous year. According to the report, they tended to be in schools in disadvantaged areas because of problems filling vacancies. Unfilled senior posts remain a particular problem in the South-east.
The proportion of schools failing their inspections has remained constant. Around 3 per cent of primaries and secondaries and 8 per cent of special schools are being added to the list annually. The secondary schools that failed this year had generally made little or no improvement since their last inspection.
The report contains a clear warning to education authorities that if they allow their failing schools to deteriorate, they will be removed from their control.
It says: "If the local authority cannot deliver, then alternative forms of provision must be found. The drive to raise standards for the children who need education most must not be allowed to grind to a halt in a mire of professional incompetence and political indecision within the local education authority."
Other key problems include the poor teaching of information technology - the least-well-taught subject of all.
According to the report, much of the investment in computer equipment is wasted because teachers lack the training and confidence to use it well.
In delivering the Government's vision, schools had to continue to focus on raising standards in the basic skills of literacy, numeracy and IT.
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MAIN POINTS FROM HM CHIEF INSPECTOR OF SCHOOLS'ANNUAL REPORT
* Teaching has improved in primary and secondary schools.
* There are an estimated 6,000 poor teachers in primaries and 9,000 in secondaries.
* Information technology is the worst taught subject.
* The proportion of failing schools remains constant at 3 per cent (8 per cent of special schools).
* Substantial underachievement identified in 10 per centof schools.
* Local authorities will lose control of schools that do not improve.
* The quality and quantity of resources are inadequate in 10 per cent of primary schools and a quarter of secondaries.
* One in eight primaries and one in seven secondaries have weak heads.
* Nine in ten of the schools re-inspected have a higher proportion of good teaching.
* The schools where teaching has got poorer tend to be in disadvantaged areas.