Almost one in 10 secondary schools are under-performing, new analysis has revealed.
Statistics show that almost 300 secondaries in England - teaching more than 200,000 children - are falling below new government targets.
Press Association analysis of Department for Education data shows huge differences in children’s access to a good secondary school.
In 46 areas of the country, all of the local secondary schools are under-performing, with the north west the worst-hit.
Schools that are considered to be failing face intervention, and a possible take over.
For the first time this year, schools were judged against a new measure called “Progress 8”, rather than on the proportion pupils achieving at least five C grades at GCSE.
The updated scoring system instead looks at the progress students make from the end of primary school to the end of secondary school, comparing them to youngsters with the same prior attainment.
Overall, 282 secondaries, educating 206,991 children, have fallen under the Government’s floor standard based on this new measure - around 9.3% of secondaries.
Despite the stark figures, this was an improvement on 2015, when 329 schools (11%) fell under the target.
Schools minister Nick Gibb said that this showed that the hard work of teachers and pupils was leading to higher standards.
“As well as confirming that the number of young people taking GCSEs in core academic subjects is rising, today’s figures show the attainment gap between disadvantaged and all other pupils has now narrowed by 7% since 2011,” Gibb explained.
He added there are now nearly 1.8 million more children in good and outstanding schools than in 2010, and the Progress 8 measure will help more children to achieve their potential.
But the National Union of Teachers (NUT) criticised the new benchmark, saying it would be a “mistake” to consider Progress 8 “a trustworthy measure of progress”.
NUT general secretary Kevin Courtney said: “The Union is concerned that in Progress 8 the DfE has introduced another measure that simplifies learning, boils down progress to a single number, and prevails upon teachers and the school leaders to organise their work around it.
“Ministers claim that the Progress 8 numbers show that educational quality is rising. That is far from the truth. Secondary schools suffer from a narrowed curriculum, from increasingly severe problems of teacher retention and an impending crisis of funding. It is to these issues that ministers should turn their attention.”