The majority of boys leave primary school without having reached basic standards in reading, writing and maths, government figures reveal today.
This year 11-year-olds faced tougher SATs exams after a government drive to improve standards.
Girls rose to the challenge with 57.1 per cent reaching the expected standard compared to less than half of boys.
For the first time pupils needed to achieve 100 in the Key Stage 2 exams rather than a level 4 under the old system.
Department for Education data released showed 50.46 per cent of boys – or 149,872 of the 296,988 males who sat the exams - failed to meet the new standard.
Meanwhile 42.89 per cent of girls did not reach the bar – representing 122,276 of the 285,028 who sat the exams.
There was a roughly eight per cent difference in success between the genders – the largest since 2012 when 29 per cent of boys and 21 per cent of girls failed to get level 4s under the old system.
Experts said girls outperform boys at a young age as they tend to be more eager to please and there are fewer male role models for boys to aspire to.
Nick Gibb, the school standards minister, said fresh efforts to raise standards through a new ‘rigorous curriculum’ meant most students "performed well" in this year’s tests.
The proportion of all students achieving the expected standards went from 80 per cent to 52 per cent under the new system as the National Union of Teachers (NUT) branded the new tests "deeply flawed" and threatened to boycott them.
New grading system
The new 100 mark is seen as equivalent of the old level 4b.
But the DfE argues the marks are “broadly similar but are not equivalent to an old level 4b.”
“However, given the curricula differences, there is not a direct equivalence between the new expected standard and level 4b there is not a direct equivalence between the new expected standard and level 4b in previous years.
“When a new curriculum and tests are introduced, evidence suggests that results will initially be lower but that they are likely to rise more quickly than normal for a few years after their introduction while pupils and teachers become familiar with the new material,” the DfE said in a report on the KS2 results.