Pupil absences as a result of coronavirus have tripled in English secondary schools indicating the worst disruption to education since March, as the Delta variant first identified in India continued to spread across the county, new data showed.

About 4.2 per cent of older students from state schools were absent on June 17 because of the virus, up from 1.4 per cent the previous week, according to figures from the Department for Education published on Tuesday.

Teacher unions have called on government for improved safety measures and more freedom to respond to outbreaks, warning that the interruption to learning could deteriorate further to levels of last winter, when up to 9-11 per cent of pupils were off for Covid-related reasons as the second wave peaked.

“We are now seeing the effect of the spreading Delta variant on national figures, and absences from school are only likely to continue rising in the coming weeks, along with obvious disruption to pupils’ education,” Mary Bousted, joint general secretary of the National Education Union, said.

“If the situation is not brought under control, the national situation . . . in schools could rapidly return to the unwelcome peaks seen earlier in the pandemic,” she added.

Covid-related absence, including children who have a suspected or confirmed case and those self-isolating as a result of exposure, doubled in primary schools, rising to 2.7 per cent on June 17 from 1.1 per cent the previous week.

The rate of Covid absence across all state schools climbed to 3.3 per cent from 1.2 per cent over the same week, accounting for about 250,000 additional pupils. The survey was adjusted to exclude exam-year pupils not expected to be in school.

Of these the majority, 2.3 per cent, were isolating having been in contact with a person inside school, while the proportion of those with the virus was 0.1 per cent. Those with a suspected case represented 0.2 per cent.

Simon Kidwell, principal of Hartford Manor primary school in Cheshire, north-west England, said the school had been largely unaffected by new cases until last fortnight, when 89 out of 400 pupils were forced to quarantine after three people contracted the virus.

“My big concern is what’s the long-term plan,” he said. “It’s massively disruptive . . . we can’t have children missing these periods of education — everybody’s really disappointed because we thought we were through it.”

The DfE said the falling attendance rate “may be impacted” by high levels of testing, as a greater number of pupils testing could have meant cases were more likely to be identified than in other groups. Under government guidance all older children should be offered two rapid lateral-flow tests a week.

The department this month updated its guidance for how schools and colleges should respond to local outbreaks of Covid, noting they should have plans in place to reintroduce testing sites on school premises and reintroduce mask wearing.

Paul Whiteman, general secretary of the National Association of Head Teachers, said it was “essential” that local public health teams were given “freedom to react quickly” to rising numbers by putting local mitigating measures in place.

“Seeking central government approval for such action only risks delaying the necessary measures,” he said.