Teaching unions have demanded clarity from government on plans to scrap the self-isolation policy in schools in England, as the education minister said he intended to lift restrictions “as early as possible”.

Gavin Williamson told MPs on Wednesday he wanted to see restrictions, including quarantine “bubbles”, removed “as quickly as possible along with wider restrictions in society”.

He said he expected to “confirm plans” along with the final stage of lockdown being lifted on July 19, and would issue guidance to schools “in plenty of time before the start of next term” in September.

But parents and teachers have expressed concern over rushing to drop mitigating measures while cases of the virus are still rising, especially among children, young people and the unvaccinated.

Paul Whiteman, general secretary of the National Association of Head Teachers, said “scrapping self-isolation for close contacts would be a very significant step to take”.

“The onus would be on the government and public health advisers to explain how the alternative arrangements would work and, most importantly, how they will maintain the safety of all members of the school community,” he said.

The announcement came after Covid-related absences in schools in England peaked at 5.1 per cent, or around 385,000 children on June 24, of whom only a small fraction had tested positive with the virus.

Under current guidance, secondary school students should test themselves for Covid-19 twice weekly, while those in contact with positive cases must isolate for 10 days. In some circumstances, this means sending home year or class-sized “bubbles” of children and teachers.

The education minister told the House of Commons that he did not see student self-testing continuing in the “much longer term”, adding: “Ideally I want to move away from that at the earliest and most realistic possible stage.”

One government official revealed on Tuesday that the education secretary was considering dropping containment measures in schools in favour of treating Covid “like any normal sickness”.

Alternatives to the “bubble” system include increasing testing and vaccinating older children, which the Joint Committee on Vaccination and Immunisation does not favour, according to members. Some schools are trialing a model to replace quarantine with daily tests for pupils who have been in contact with positive cases.

Deepti Gurdasani, a clinical epidemiologist and senior lecturer at Queen Mary University in London, said the government had created a “false dichotomy” between keeping children in school while Covid spreads freely and containing the virus and disrupting education.

Other measures, such as wearing face masks or improving ventilation in classrooms could help control transmission, she added, while vaccinating children was the “next logical step”.

Kevin Courtney, general secretary of the National Education Union, which represents teachers, demanded clarity on whether bubbles would be swapped for daily testing. If so, the strategy should be subject to proper scientific scrutiny and teachers clearly told what support they would receive.

He added that government should provide guidance on the severity of long Covid in children if it “intends to let cases rise in an uncontrolled way”.

“The DfE needs robust answers to these questions,” he said. “We all hope for the best — but we cannot just rely on hope.”

Shamez Ladhani, a consultant paediatrician at St George’s Hospital in London, said controls in schools were “a temporary measure,” adding: “We’re not quite there yet to ease restrictions in schools.”

Even if vaccinations were rolled out to the aged 12 and above, preventing infections in schools was “unrealistic”, he said.