There has been a general rise in standards, but one in 10 schools are said to have serious weaknesses.

Chief Inspector Chris Woodhead

And different schools with similar pupil intakes show marked variations in quality.

Although two out of five secondary schools are consistently good, one in 10 has significant weaknesses and just over one in 50 fails to provide an acceptable quality of education.

BBC Education Correspondent Sue Littlemore reports

The report, billed as the most comprehensive analysis of secondary education ever published, is based on the inspections of every one of the 3,594 secondary schools in England between 1993 and 1997.

More than 500,000 lessons were observed by inspectors, who examined the standards achieved by pupils, the quality of teaching, the effectiveness of school leadership and management, and a range of other indicators including pupil behaviour.

The report also finds that the amount of money spent per secondary school pupil has fallen in real terms over a five-year period and that pupil/teacher ratios have risen.

The government is due to issue a response to the findings.