More than 700 primary schools in England fall below the Government's new tougher standards in reading, writing and arithmetic, Department for Education figures suggest.
For the first time, schools are judged on the number of children achieving at least a Level 4 - the standard expected of the age group - in reading, writing and maths.
They must ensure that at least 60% of pupils reach this level in all three subjects and meet national averages in pupil progress.
In previous years, they were rated on reading and writing combined to form an overall English result and maths, as well as progress.
The 767 schools that fail to meet the target are considered under-performing and face being taken over and turned into academies.
More top news
Labour's billboard posters during the general election campaign will focus on 'issues not personalities', the party's strategist has said.
Scientists find a cluster of spinal neurons integrate sensory data and unconsciously adjust muscles to maintain balance and avoid slipping.
Billionaire businessman Stefano Pessina has said the Labour leader's economic plans are "not helpful for business or the country."