More than 50 schools have announced pupils and staff will be made to wear face masks – in defiance of Boris Johnson.
The Oasis Academy chain, which has 32,000 pupils across 52 schools in England, said face masks will be considered part of the school uniform when they reopen next week.
It comes as the UK government continued to resist calls for face masks to be made compulsory in schools in England, though Johnson later said it will consider “changing medical evidence as we go on”.
In contrast, the Scottish government has announced “obligatory guidance” for face masks to be worn in secondary school corridors and communal areas – as well as on school transport – from Monday.
Steve Chalke, founder of the Oasis Academy, told the BBC on Tuesday: “We believe this [face mask policy] makes our schools safer than they would otherwise be.”
Chalke, who said it is “all about common sense and taking responsibility”, added: “There is no such thing as being COVID-safe, just COVID-safer.
“Based on our values and our sense of morality, these are the moves that we are choosing to make.”
Though the 52 schools are going against government guidance, Chalke later insisted he was not “rebelling” against Johnson and that he is “trying to enact what Boris has asked us to do”.
The government guidance for schools in England does not currently recommend face masks because pupils and staff are mixing in consistent groups.
It adds that misuse may inadvertently increase the risk of transmission, while it could also have a negative effect on communication.
However, the World Health Organization (WHO) has recently advised that pupils aged 12 and over should wear a mask.
Asked why the government was ignoring the WHO advice, Johnson told reporters on Tuesday: “The overwhelming priority is to get all pupils into school.
“And I think that the schools, the teachers, they’ve all done a fantastic job of getting ready. And the risk to children’s health, the risk to children’s wellbeing from not being in school, is far greater than the risk from COVID.
“If there are things we have to do to vary the [face mask] advice on medical grounds, we will, of course, do that.
“But as the chief medical officer – all our scientific advisers – have said, schools are safe.”
It came after the Association of School and College Leaders (ASCL) union urged Downing Street to review its guidance.
General secretary Geoff Barton told the Daily Telegraph: “The evidence is clearly evolving on this issue and it is important that it is kept under review, and that clear direction is provided to schools.”
Kevin Courtney, joint general secretary of the National Education Union, also said on Tuesday: “We have to stay abreast of the science, so when the WHO says that children over 12 should wear masks in communal areas at school, that ought to be listened to.”