Hundreds of schools have been urged by their council to reintroduce stricter COVID measures amid fears over rising cases.
Staffordshire County Council, which covers 400 primary and secondary schools, has reportedly recommended that measures including bubbles and contact-tracing be brought back in.
It comes as experts warned on Thursday over rising numbers in school pupils, with one saying children under 18 are facing "one of their worst periods of the pandemic" in terms of COVID cases and admissions.
Education Secretary Nadhim Zahawi has said that mask-wearing for pupils could return under contingency plans to keep coronavirus at bay over winter, but said he didn't want to see the reintroduction of bubbles because of the disruption they cause.
Current government guidance sets thresholds for the reintroduction of stricter measures in individual schools in response to high case rates in that school.
But Schools Week reported that a briefing has been issued to headteachers in Staffordshire by the county council outlining "recommended controls" aimed to prevent COVID outbreaks and manage transmission of the virus.
The document includes the recommendation of the reintroduction of class bubbles for primary schools, as well as year-group bubbles for secondary schools.
It also suggests that primaries should scrap events that involve the whole school like assemblies and all-staff meetings, as well as staggering lunch breaks, while measures for secondaries include reintroducing face coverings in social spaces and consider changing the way PE lessons are run.
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According to Schools Week, the council also wants all schools to contact trace whole classes or years if they have mixed, rather than “wait for track and trace”, while pupils with confirmed household cases are advised to "stay at home pending PCR test result", even if schools cannot legally require isolation.
Figures from government coronavirus data shows that there were 485.4 cases per 100,000 in the week up to 3 October in Staffordshire, compared to an average of 331 in England.
Councils in some areas, including Wolverhampton as well as Cambridgeshire, have asked schools to reintroduce mask-wearing in communal areas to try to manage rising cases.
Julie McCulloch, policy director at school leaders’ union ASCL, told Schools Week that councils were making area-wide decisions amid "confusion" and a "lack of clarity" over who is responsible for the introduction of stricter measures.
In a letter to parents, the head of one Staffordshire high school reportedly told parents she was "sad" to be announcing new COVID measures.
In the letter seen by Schools Week, Debbie Bailey, head of Queens Croft High School in Staffordshire, said single-class bubbles were being considered but the school was reluctant.
Her letter reportedly highlighted key stage "bubble boundaries", virtual school meetings and no off-site mixing with other schools.
The school has been approached for comment.
Jonathan Price, Staffordshire County Council’s Cabinet Member for Education, said: "Like other parts of the country, Staffordshire has seen a significant increase in cases linked to schools.
"Cases of COVID-19 continue to be high in Staffordshire, largely due to outbreaks in schools and colleges among the 11-to-18 year age group.
"In order bring down the case rates, reduce the risk to the wider community and minimise the disruption to education we are deploying a Mobile Testing Unit at Staffordshire schools to offer PCR tests to students. This will help identify more pupils who may unknowingly have the virus and in turn help prevent the spread of infection.
"We want to keep schools open and children in school, so like other authorities we have outlined some measures schools may potentially want to consider on a case-by-case basis. This could include enhanced cleaning or trying to keep pupils in bubbles. This would be to limit contact and not for isolation purposes.
"Our schools and children have shown tremendous resilience throughout the pandemic, and we will continue to support them to reduce cases of COVID-19."
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