The proportion of secondary schools that are partly closed has increased to more than one in five, new figures show.

The Department for Education data shows that the figure for fully open secondary schools has dropped to 79 per cent, from 82 per cent a week earlier.

However, the department said that figures suggest schools are not asking as many pupils to self isolate as a result of the coronavirus, with attendance within partly closed secondary schools increasing.

Attendance: Nine in ten pupils in school at the start of term

Covid-19: Schools in England forced to close

Cases: Teacher union demands action after rise in cases among 10 to 19-year-olds

The latest figures are based on the data reported by schools on Thursday 8 October, compared with the week previously.  

It shows that overall around 91 per cent of state-funded schools were fully open compared with 92 per cent a week earlier.

Notes published by the department state: “Of the schools which were not fully open, most were not fully open due to Covid-19 related reasons”.

The data also shows that 99.8 per cent of state-funded schools were open, the same as last week.

And approximately 90 per cent of all children on roll in all state-funded schools were in attendance, which was also the same as last week. 

The DfE notes add: “When pupils are unable to attend school because they are complying with clinical or public health advice, schools are expected to be able to immediately offer them access to remote education.”

The latest figures follow a Tes investigation that showed around one in five schools have had cases of Covid-19 in the first month of term.

Commenting on the latest Department for Education school attendance statistics, Geoff Barton, general secretary of the Association of School and College Leaders, said: “The number of fully open secondary schools has fallen for the third week in a row, reflecting the extremely difficult circumstances in which schools are continuing to operate amidst rising Covid infection rates.

“School leaders and their staff deserve great credit for the huge amount of work they are putting into managing complex control measures while delivering education for those in school as well as those who are at home self-isolating.

“The pressure is immense and we are increasingly concerned about the mental health and wellbeing of school leaders and their staff. There is much that the government could and should do to relieve the sources of stress that it can control.

“It is ludicrous to resume Ofsted inspections in January, as currently planned, in light of so much disruption and these should be suspended for this academic year. School performance tables have to be ruled out given that it is impossible to compare schools fairly in these circumstances.

“And the government must reimburse schools for the cost of implementing Covid safety measures, which are putting tight budgets under even more strain.”

Education secretary Gavin Williamson said: “Regular and full-time attendance in school is absolutely essential to help pupils catch up on time out of the classroom. It is encouraging to see the vast majority of schools are open, as has been the case since the start of term, and more than 7.4 million pupils are attending.

“Attendance in fully open primary schools is now consistent with what we would have expected before coronavirus. Across all state schools, only a small minority of pupils are self-isolating and schools are providing remote education, in line with what pupils would be receiving in school.

“We will continue to work with schools to ensure all appropriate steps are taken to keep pupils and staff safe.”