The absence rate for UK pupils rose over the autumn term in 2019-20, from 4.3 per cent overall during the same period in 2018-19 to 4.93 per cent, new data shows.
That makes the overall rate easily the highest in six years, since 2012-13 when it was 5.2 per cent.
The figures, published today by the Department for Education, also show that the unauthorised absence rate increased from 1.2 per cent to 1.32 per cent in the same period.
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The percentage of persistent absentee pupils across all schools rose by more than a fifth, from 10.9 per cent to 13.14 per cent.
Increase in school absence 'down to illness'
A statement on the DfE website said: "In recent years, autumn term absence rates have given reasonable indications of trends in the full year of data.
"However, absence in a single term can be more affected by the level of seasonal flu or other illness than the full year and this has been the main driver for the increase in the absence rate from autumn 2018 to autumn 2019."
According to the DfE, illness is the most common reason for absence, accounting for 58 per cent of all absences, and the main driver for an increase in pupil absences in the 2019 autumn term, with the number of days missed due to illness increasing by 22 per cent.