The number of pupils regularly missing school in England has not returned to pre-Covid pandemic levels, according to official statistics.
A quarter (25.1%) of pupils were persistently absent last term, compared with 13.1% in the autumn term of 2019.
The government said the absence rate was driven by illness, with high levels of flu and other viruses circulating.
It said it was “offering targeted help” for children who were regularly off school.
But a union representing school leaders has said illnesses are only part of the picture.
The Association of School and College Leaders attributes many absences to high levels of pupil stress and anxiety, long waits for mental health treatment and “disengagement” with education as a result of the pandemic.
MPs on the Education Select Committee have launched an inquiry into the issue.
Pupils count as persistently absent if they miss 10% or more of school sessions, which would amount to seven days in the autumn term.
The percentage of persistently absent pupils stayed at around 11% in the 2016 to 2018 autumn terms, and reached 13.1% in 2019.
The following year, persistently absent children came to include those who tested positive for Covid.
The government also started registering children who were “not attending” school because of public health guidelines, which included pupils who were out of school while waiting for the results of a Covid test.
In autumn 2020, the first year of the pandemic, 44.6% of pupils missed 10% of lessons or more. Of those, 13% were marked as absent, and 31.6% as not attending due to guidelines.
In the same term the following year, that overall figure fell to 32.2%. However, the breakdown flipped, with 23.5% of those marked as absent and 8.7% as not attending due to guidelines.
The government has scrapped the “non attending” category this academic year, and 25.1% of pupils were marked as absent in autumn 2022.
As a result, it says, the persistent absence rate was higher than in 2021 (when it was 23.5%), but more children were in school.
The Department for Education said it was working with schools, councils, and governing bodies to “identify pupils who are at risk of becoming, or who are persistently absent and working together to support that child to return to regular and consistent education”.
The Education Select Committee recently said Covid was “likely to have had a damaging affect on school attendance”.
Pupils experienced disruption to their education when schools closed during Covid lockdowns in 2020 and 2021.
At the end of last year, levels of flu, scarlet fever, Strep A and Covid were high.
The committee was also looking at why disadvantaged pupils and those with special educational needs and disabilities (SEND) were more likely to miss school than their peers.
Geoff Barton, general secretary of the Association of School and College Leaders, said the evidence from school leaders shows “pupil attendance continues to be very challenging for a number of reasons”.
“Illness is a factor due to Covid and seasonal viruses, but on top of that there are high levels of pupil stress and anxiety, which are not helped by very long waits for specialist mental health services, and disengagement among pupils who have never quite recovered the habit of regular attendance following the pandemic.
“Schools do their best to encourage good attendance, but they need more support from local authority attendance services which have been reduced because of government cuts.”