According to the School Curriculum and Assessment Authority, such improvements are to be expected in this, the second year of testing. But the figures, taken from a sample of 10,000 papers, could none the less be useful ammunition for Education and Employment Secretary Gillian Shephard as she fights the teaching profession over primary league tables and re-introducing grammar schools.

In last year’s tests for 11-year-olds, 48 per cent reached level 4 or above in English, compared with 56 per cent this year. In maths, the focus of much concern, 44 percent reached the same level last year, a figure now up to 57 per cent.

These improvements are set against a marked decline in the science results. The proportion reaching level 4 fell from 70 per cent last year to 62 per cent this year.

A spokeswoman from SCAA said that changes to the tests made comparisons with last year difficult. In maths, for example, pupils were given an extra 10 minutes while the science tests were deliberately made harder in an effort to equalise the difficulty across subjects.

She said that the results were expected to improve in the second year of testing at key stage 2, just as they did at key stages 1 and 3.

The sample of 10,000 scripts has been used as a way of moderating the grades awarded. This gave rise to concern on the part of some unions, the National Association of Head Teachers in particular, which believes this sort of last-minute adjustment is further evidence that the tests are still at an experimental stage.

However, SCAA says that only one grade, level 5 in science, was altered as a result. This does not affect the aggregate figures of those reaching the benchmark level 4.