Disadvantaged children have fallen behind their more affluent peers in maths by an extra month since the start of the pandemic, a study suggests.

The attainment gap between poorer primary school pupils and their classmates has grown in maths since schools were first closed due to Covid, research from the Education Endowment Foundation (EEF) charity has found.

While poorer pupils’ outcomes in maths seem to have been hit hardest by the first lockdown, the attainment gap did not widen or shrink during the autumn term when schools fully reopened.

Researchers suggest that the disadvantage gaps caused by the pandemic are proving challenging to close in primary schools despite all pupils returning to class in September – and they are unlikely to narrow without intervention.

The cost of failing to act now will be a catastrophe for young people from low-income homes

Prime Minister Boris Johnson has already made £1.7 billion of catch-up funding available in England to help children who have faced disruption from school and college closures due to Covid-19.

But EEF chairman Sir Peter Lampl is calling for significant Government funding to mitigate against the long-term impact of school closures as he warns failing to act now will be “catastrophe” for disadvantaged children.

The study is based on reading and maths assessment data collected by FFT Education from 132 primary schools in England in autumn 2019, prior to the pandemic, and in September 2020, after the first national lockdown, and then again towards the end of autumn term.

It looked at the differences in progress between pupils eligible for free school meals and their peers in Years 2 to 6, rather than measuring the overall impact of school closures on learning loss.

The interim findings from the study found that pupils from deprived backgrounds have fallen further behind in maths – with the attainment gap widening by a further month since the onset of the pandemic.

But the research found no discernible change to the disadvantage gap in reading.

The findings also highlight the difficulty of tackling educational inequality in classrooms.

Research studies like this one are providing clear evidence that substantial existing gaps have grown further due to the disruption to learning caused by the pandemic

Data collected from assessments taken by pupils at the end of the autumn term indicates that the return of all pupils to school in September has not been enough to narrow the newly widened gap.

Sir Peter, who is also the founder of the Sutton Trust educational charity, said: “Today’s research gives us more evidence of the enormous impact school closures have had on young people, especially those from low-income homes.

“The research indicates the need for long-term, sustained support for schools as they work to accelerate the progress of their disadvantaged pupils.

“To mitigate against the long-term impact of lost learning, large government funding is required. The cost of failing to act now will be a catastrophe for young people from low-income homes.”

Professor Becky Francis, chief executive of the EEF, said: “The pandemic has brought the significance of social and educational inequality into sharp focus.

“Research studies like this one are providing clear evidence that substantial existing gaps have grown further due to the disruption to learning caused by the pandemic.

This research confirms what we feared - that the education attainment gap between disadvantaged children and other children has grown during the pandemic

“In strategising an approach to recovery, we are presented with the opportunity to go beyond restoring the learning lost during partial school closures, and work towards rebalancing the scales for disadvantaged pupils.”

Tiffnie Harris, primary specialist at the Association of School and College Leaders (ASCL), said: “This research confirms what we feared – that the education attainment gap between disadvantaged children and other children has grown during the pandemic.

“This latest research will not come as a surprise to primary leaders, who know the learning needs of the children in their schools better than anyone else.

“This report reinforces the pressing need for a robust and fully funded education recovery plan in which school leaders must be in the driving seat of deciding what will work best for their pupils.

“This recovery plan must take the opportunity to address the attainment gap which already existed before the pandemic struck and which has gone on for far too long.”