Covid-19 is widening the attainment gap between disadvantaged children and their better-off peers, a study suggests.

Analysis by the Education Endowment Foundation (EEF) – which looked at various reasons for school shutdowns ranging from summer holidays, adverse weather, teacher industrial action, natural disasters – estimate the gap could widen from 11% to 75%.

Over the past decade the attainment gap between disadvantaged pupils and their classmates at the end of primary school is estimated to have narrowed, from 11.5 months in 2009 to 9.2 months in 2019, according to the Education Policy Institute.

The EEF fears that progress made since 2011 will be reversed.

The analysis states: “The projections suggest that school closures will widen the attainment gap between disadvantaged children and their peers, likely reversing progress made to narrow the gap since 2011. The median estimate indicates that the gap would widen by 36%.”

Pointing out that sustained support will be needed to help disadvantaged pupils catch up, it adds: “It is highly likely that the gap will have widened when pupils return to school, even if the strongest possible mitigatory steps are put in place.

“It is highly unlikely that a single or short-term catch-up strategy will be sufficient to compensate for lost learning due to school closures.

“There is a risk that high levels of absence after schools formally reopen poses a particular risk for disadvantaged pupils.”

It looked at 11 studies to examine the potential impact of school closures on the attainment gap.

It points out there has previously been no unplanned closures of the length already experienced by schools in England due to the coronavirus pandemic and that the existing evidence on school closures almost exclusively focuses on summer holidays and younger children.

EEF chief executive Professor Becky Francis said: “The evidence is clear that children learn less when they are not in school. Our analysis today highlights that this particularly impacts those from disadvantaged backgrounds and widens the attainment gap.”

Ravi Gurumurthy, chief executive at Nesta, the innovation foundation, said: “The school closures from Covid-19 are widening inequalities in educational achievement.”

The EEF and charities including the Sutton Trust, Impetus and Nesta have launched an online tuition pilot to help support up to 1,600 disadvantaged pupils.

They hope it can help minimise the size of the gaps that are opening up – both while pupils are learning remotely and as they begin to return to school.

The pilot is set to include online tuition in core subjects using structured workbooks for up to 100 students in Years 6 and 10 plus one-to-one tuition for up to 1,000 pupils in years 10/11.

Support for 440 students in Years 10/11 and Years 12/13 who would normally receive face-to-face tuition and one-to-one online tutoring for 100 students in Years 5 and 10 is also set to be on offer.

Andy Ratcliffe, chief executive of Impetus, added: “Tutoring boosts children’s learning and better-off children get more of it than those from disadvantaged backgrounds – that was true before Covid-19 struck and the tutoring gap has widened even further during lockdown.”

Russell Hobby, chief executive of Teach First, a charity which aims to address educational disadvantage in England and Wales, said: “It’s devastating that children from poorer backgrounds risk having their education interrupted by this pandemic. Nearly 10 years of progress in narrowing the gap wiped in a few months is tragic.

“This is deeply unfair for these children. We must tackle this head on, standing behind the teachers and schools fighting this injustice daily.

“This does start with intensive catch-up provision when possible, but also means weighting resources and funding towards the schools and pupils who have suffered the most.”

Education Secretary Gavin Williamson said: “We know that being in school is vital for children’s education and their wellbeing, which is why we are pleased to see so many children begin to return to school this week.

“This innovative online tuition pilot is an important part of plans to put support in place to ensure young people don’t fall behind as a result of coronavirus, particularly those facing other disadvantages.”