Research has shown that ministers have "grossly exaggerated" improvements in primary school performance.

The Association of Teachers and Lecturers said last night that standards have risen in recent years but by a smaller margin than test results indicate.

Teachers' leader Mary Bousted said that primary test results, known as SATs, are "not statistically significant" and represent poor value for taxpayer's money.

While she acknowledged that schools have improved, she suggested that testing five to 11-year-olds was a waste of money.

Pointing to research conducted by Professor Colin Richards from Lancaster University the ATL general secretary said: "The changes we have seen to date are not statistically significant.

"Claims made about significant upward trends are grossly exaggerated.

"They cannot in any sense represent value for the millions of pounds from the public purse that have been spent on the national strategies and statutory assessments.

"The most we can say about rises or falls in standards, as measured by the SATs, is that the evidence suggests that there was some rise in performance in the core subjects between 1995 and 2001 as measured by test results, but not as great as national test data (and the government) have suggested."