PRIMARY-age pupils' performance in reading and maths has dropped significantly following school closures during the first lockdown, a study suggests.
There is a "large and concerning" attainment gap between disadvantaged pupils and their more affluent peers.
Research from the Education Endowment Foundation (EEF) found the gap is estimated to be the equivalent of seven months' learning for both reading and maths.
Interim findings from the study suggest that Year 2 pupils in England had a lower achievement in the autumn as a likely result of missed learning.
Pupils, on average, were making around two months' less progress in maths and reading in autumn 2020 compared to a 2017 cohort, the research said.
The study was based on data collected by the National Foundation for Educational Research from assessments taken in November by nearly 6,000 six and seven-year-olds in England.
End of year assessments in maths and English have not taken place in P6 and P7 in Northern Ireland due to school closures. Most children last took these in P5.
Some schools, concerned that grammars might use results of standardised assessments to select pupils, brought P7s back in recent weeks to sit them.
The Department of Education later warned schools that this was not permitted.
EEF chairman Sir Peter Lampl said by the time schools reopen, children will have faced almost a year of learning disruption.
"The repercussions of these months of lost learning are devastating and will be felt for a lifetime, especially by those from low-income backgrounds," he said.
Geoff Barton, general secretary of the Association of School and College Leaders, said the "bleak findings" emphasised the need for more catch-up support for pupils whose education has been disrupted by the pandemic.
