The Office for Standards in Education's report on the first year of the national primary strategy is likely to emphasise the need for English and maths to be part of a broad, stimulating timetable.
It will also highlight the importance of school leadership on pupils' results.
League tables published this week show that 75 per cent of 11-year-olds reached the expected level in English tests for the fourth year running and 73 per cent did in maths for the second year.
At the start of the year, Stephen Twigg, minister responsible for primary schools, told heads that pupils were not making enough progress in English and maths in one in four schools. He committed pound;42 million to booster classes for underperforming children in Year 6. Extra funding of pound;11m was also made available to train teachers, assistants and to run extra classes in English and maths over Easter.
But this year schools have been told they no longer have to spend money on booster classes.
Mr Bell said: "If you look at the plateauing of results over the past three or four years it appears that booster classes, a late intervention to rachet up performance, have not necessarily had that effect.
"Some children are genuinely very close to that level of achievement and that last-minute work will make all the difference. That is quite different from children who have a shaky knowledge but with special coaching would be able to pass the test.
"Headteachers must focus on what individual pupils are doing and what interventions teachers need to adopt."
Primary league tables report 12 amp;13