Achievement for All, commissioned in January by the Secretary of State, will be seen as a landmark that may herald the end of 25 years of mixed-ability teaching and the “fresh start” in early secondary. Both the Government and Labour have backed setting as a way of raising standards.

Schools will be urged to reconsider how they organise teaching and learning, although there are no plans at present to legislate. The Government favours a more informal approach based on professional co-operation. Schools that continue with mixed-ability teaching will, however, have to justify their approach in inspections.

On the back of what may prove among the most contentious of recent education reports, the Inspectorate is to launch a further probe into the apparent failings of teaching and organisation in the first two years of secondary, a long-standing concern. More setting will not solve all the difficulties, HMIs admit.

Douglas Osler, senior chief inspector of schools, yesterday (Thursday) distanced the report from other political considerations, although it will be difficult for the Inspectorate to dissociate the findings from the forthcoming consultation on compulsory national testing in the first two years of secondary school and the Government’s White Paper on education.

Mr Osler said: “This is a professional report offering professional advice to other professionals. It is based on more than 20,000 classroom visits by inspectors. I believe the Inspectorate has a role in offering a professional lead to the profession on difficult and controversial issues such as this. ”

The recommendations were signalled two years ago in the practical guide to the 5-14 programme. Primaries already use attainment groups in mixed-ability classes as a method of setting, Mr Osler said, and secondaries use setting more in S2 than S1. The advice to schools and local authorities is also based on evidence from the Assessment of Achievement Programme and from international research.

In primaries, maths and English language should be organised in attainment groups and there should be no more than three groups per class. Over time, other aspects of the curriculum should be similarly organised. Large primaries, with more than one class at each stage, should consider setting across the year in P6 and P7.

In secondaries, more use should be made of attainment groups in all subjects. Broad band setting should be introduced in mathematics and English language in S1 and, where feasible, in some other subjects by S2, particularly in science and modern languages.

Ruling out streaming, which is rarely found in Scotland, the report says it is inflexible, discourages pupils in the lower streams and does not take account of prior learning.

Achievement for All, A report on selection within schools. HMSO Pounds 5.