Poorer pupils in disadvantaged “opportunity areas”, designated for extra help by the government, are lagging almost two years behind better off counterparts elsewhere in England.
A study for the Ambition School Leadership charity found deprived youngsters in these six areas were 20.1 months behind at GCSE level.
Schools minister Nick Gibb said it showed the importance of targeting support at areas that were “the most challenged when it comes to social mobility”.
There have been six opportunity areas named by the government so far – Norwich, Blackpool, Derby, Oldham, Scarborough and West Somerset – with the promise of more to follow.
There will be £60m of extra spending to promote social mobility in these areas, such as linking schools to businesses, universities and careers advisers.
The study shows how far “persistently disadvantaged” pupils – who have been eligible for free school meals for four out of five years – have fallen behind in secondary school.
They were found to be the equivalent of 20.1 months behind the average for children who were not on free school meals in other parts of England.
Pupils in the “opportunity areas” who were not on free school meals were also behind their counterparts in other parts of England – by 4.7 months.
The study looked at pupil achievement between 2010 and 2015 and found that the gap had widened.
Ambition School Leadership has been created from bringing together two education charities, Future Leaders Trust and Teaching Leaders, which had worked to improve school leadership, particularly in disadvantaged areas.
James Toop, chief executive of the new charity, said: “We know great leaders at all levels make great schools. We’re going to be working even harder to reach these schools and give the children they serve a great education.”
School Standards Minister Nick Gibb said the study showed the need for the government’s plans to “make more good school places available, to more parents, in more parts of the country”.
He said this would include “scrapping the ban on new grammar school places and harnessing the resources and expertise of universities, independent and faith schools”.
“This report underlines the need to focus our efforts in the areas identified as the most challenged when it comes to social mobility.”
A separate study from the the Education Policy Institute looked at Ofsted inspections in schools with a more disadvantaged intake.
The researchers claimed inspectors were more likely to have harsh judgments on schools with higher proportions of pupils on free school meals – and that they could be too generous to those with a wealthier intake.
An Ofsted spokeswoman rejected this claim, saying that inspectors would “mark down coasting schools in leafy suburbs where we see pupils not making as much progress as they should”.
“Similarly, we do recognise schools in more deprived areas where children are making good progress.”
Schools in England could need an extra 19,000 head teachers and deputies within the next six years, education charities are warning.
The Future Leaders Trust, Teach First and Teaching Leaders say the new leaders will be needed as pupil numbers rise and large numbers of heads retire.
They also highlight the need for extra school leaders as more schools switch to academy status.
The Department for Education says it does not recognise the figures.
The latest school workforce data shows that there are 68,800 full-time equivalent leaders in state schools in England.
The DfE adds that since 2010 the proportion of schools reporting a head teacher vacancy has decreased, while the number of school leaders over the age of 50 has decreased significantly.
But a report by the charities, entitled the School Leadership Challenge, says that 3,800 schools do not have enough leaders currently to enable them to operate in the best way possible.
And it calculates that while between 16,000 and 20,000 heads and deputies will reach retirement age by 2022, there are not enough teachers coming through schools to replace them.
About 65% of school leaders are aged over 45, which means there will be large numbers of retirements over the next 10 to 15 years, the report says.
It also argues that as more schools convert to academy status there will be a need for between 4,000 and 8,000 more leaders, as the academy programme tends to create another level of management.
Most trusts tend to have a chief executive officer and an executive head overseeing a number of schools, and these posts are pulling large numbers of senior head teachers out of traditional school headship roles.
‘Action needed now’
And through a complex model including population projections, retirement rates and predicted rates of conversion, the report concludes some 19,000 head teachers will be required.
It says schools already face recruitment challenges, with many struggling to attract high quality applicants and spending thousands of pounds on recruitment campaigns.
Salaries for head teachers vary from around £54,000 at a primary school to as much as £108,000 at a large secondary.
Chief executives running a number of schools in an academy chain can earn £250,000 a year.
The charities recommend one way to ease the shortage would be to recruit executives from other organisations or business to run schools.
Malcolm Trobe, interim general secretary of the Association of School and College Leaders, said: “Many more school leaders will be needed over the next few years and it is vital to take action now to address this issue.”