Almost 200,000 children are at primary schools which are considered to be under-performing, in the wake of controversial changes to SATs tests, official figures show.
In total, 665 mainstream primaries in England fell below the Government's floor standard this year, according to the Department for Education (DfE).
The statistics also show wide regional variations, with children in London the most likely to get a decent education, while those in the South West and the East Midlands are the least likely to get access to a good primary school.
The latest data come after a tumultuous year for primary assessment, including major changes to toughen up the tests and concerns raised by teachers and school leaders about pressure on pupils and unreliability of results.
School Standards Minister Nick Gibb said this year's SATs tests - or national curriculum tests - are the first to test pupils on a new primary curriculum introduced in 2014, which was brought in to "raise expectations" and ensure youngsters get a good grounding in the basics.
But one union leader slammed the results, saying the data "is not worth the paper it is written on."
Schools are considered under-performing if fewer than 65% of pupils fail to reach the expected standard in reading, writing and maths, or if they fail to make sufficient progress in these three key areas.
Overall, five percent of primaries fell below the government threshold this year. Education Secretary Justine Greening had previously pledged than no more than six percent would be below the benchmark. She also promised that no school would face outside intervention based on this year's data alone.
According to Press Association analysis of the data, around 180,743 children are being taught at the 665 primaries that failed to meet the Government's new threshold. This is around 4.1% of the total number of youngsters at mainstream primary schools in England.
Across England, 53% of the almost 600,000 11-year-olds who took the tests reached the expected standard in reading, writing and maths this year.
A breakdown shows that in the capital, just 1% of schools were below the floor standard, compared with 7% in both the South West and East Midlands.
And poor children are falling behind their richer classmates - 35% of children eligible for free school meals reached the expected standard in all three areas this year, compared with 57% of those who do not receive free dinners.
Mr Gibb said: "This year's SATs are the first that test the new primary school curriculum in English and maths that we introduced in 2014. This new curriculum raises expectations and ensures pupils become more accomplished readers and are fluent in the basics of arithmetic, including times-tables, long division and fractions.
"Many schools have responded well to this more rigorous curriculum, supporting their pupils to be leaving primary school better-prepared for the demands of secondary school."
Previously, pupils were awarded "levels", with Level 4 the standard expected at the end of primary school. These "levels" have been scrapped and students are expected to reach a new standard based on scaled scores in each subject. The new expected standard has been set at a higher benchmark than the old Level 4.
This year's SATs tests have been fraught with controversy. Teachers raised concerns about the difficulty of the tests - particularly the reading paper, while school and union leaders warned that there had been a lack of guidance for schools on the new tests, and argued that the data gathered from the results is "misleading".
In May, the answers to the Key Stage Two grammar, punctuation and spelling test appeared on a password-protected area of an exam board website for several hours before being removed. A ''rogue marker'' was blamed by the government for the attempted leak.
Russell Hobby, general secretary of the National Association of Head Teachers (NAHT), said: "This data is not worth the paper it is written on. The government itself has said that it cannot be used to trigger interventions in schools, nor can it be compared to previous years.
"This year, we saw the SATs system descend into chaos and confusion. Delayed and obscure guidance, papers leaked online, mistakes in test papers and inconsistent moderation made this year unmanageable for school leaders, teachers, parents and pupils.
"The data gathered in primary assessment during 2016 is misleading. We warned the government that publishing this data in league tables could lead the public and parents to make poor judgments about a school's performance, but it has still chosen to do so."