"Almost no impact" has been made on reading skills despite £500 million being spent on raising English standards in primary schools.A major review has found pupils feel increasingly stressed about school tests and are losing their love of books in the drive to improve literacy levels.Reading standards have barely improved since the 1950s, researchers at the Primary Review, based at Cambridge University, found.They are calling for a major overhaul of the primary school testing regime amid warnings the current system could be giving up to a third of children the wrong grades.As part of the biggest inquiry into primary education for decades, the Primary Review published three reports from academics at the universities of Bristol and Durham and the National Foundation for Educational Research.The Durham University study, led by Professor Peter Tymms, warned the Government's "massive efforts" had brought little reward.The National Literacy Strategy, which includes the literacy hour daily English lesson in schools, had made a "barely noticeable" impression on reading standards.The study said the apparently dramatic rise in primary school test results in the last decade vastly overstated the true scale of improvements.The report said: "The rises exaggerated the changes in pupils' attainment levels and were seriously misleading."Professor Tymms has riled ministers in the past for suggesting that tests do not reflect the true nature of rising standards. But the independent statistics watchdog has backed his conclusions.Schools Minister Lord Adonis rejected the review's findings, saying: "Primary standards are at their highest ever levels. This is not an opinion, it is fact."The minister said this year's test results showed that 84 per cent of 11-year-olds achieved the expected level for their age group, up 17 percentage points since 1997."We know that in the post-war period improvements in reading were static," he said."It was precisely this analysis that led us in 1997 to seek a step-change in literacy through the introduction of the national strategies and daily literacy hour, an emphasis on phonics, and training for every teacher in literacy."This has worked."Liberal Democrat schools spokesman David Laws said: "There should be a real concern that the report shows that enjoyment is being squeezed out of learning."We must not turn our schools into factories producing test results, they must be places where creativity and ambition are allowed to flourish."© Independent Television News Limited 2007. All rights reserved.