The government has told a London council it must keep schools open or face legal action.
Greenwich Council had written to head teachers asking all schools to move classes online from Tuesday amid rising Covid-19 cases.
On Monday evening, Education Secretary Gavin Williamson ordered the south-east London council to keep schools open.
He said: “Using legal powers is a last resort but continuity of education is a national priority.”
Ofsted said it was right to keep schools open as children were “suffering” from “yo-yoing in and out of school”, while parents criticised the timings of the announcements and questioned the politics behind the move.
In Islington, north London, and Waltham Forest, east London, schools were also asked to move lessons online from the end of Tuesday. All three councils are Labour-run.
Mr Williamson added: “It is simply not in children’s best interests for schools in Greenwich, Islington or elsewhere to close their doors.
“That’s why I won’t hesitate to do what is right for young people and have issued a direction to Greenwich Council setting out that they must withdraw the letter issued to head teachers on Sunday.”
In the letter sent out on Sunday, Greenwich Council Leader Danny Thorpe asked all schools to move the majority of pupils to remote learning.
The council told schools to keep buildings open for vulnerable children and those of key workers.
The regional schools commissioner, who acts on behalf of the education secretary, had already written to Greenwich Council highlighting that new powers, introduced through the Coronavirus Act, allowed the secretary of state to issue “directions” to require schools to enable all pupils to attend school full-time.
The Department for Education said no decisions had been taken yet about what action to take against Greenwich, Islington and Waltham Forest councils.
Greenwich Council said changing plans that had already been put in place before Tuesday would be “impossible”.
Mr Thorpe said the council was seeking legal advice and would respond to Mr Williamson on Tuesday morning.
“Schools across the borough have now organised online learning from tomorrow (Tuesday), whilst others are opening their premises to all pupils,” he said.
“We have alerted schools and will speak to them tomorrow.
“But given we received this notification just before 17:00 GMT, it was impossible to ask schools to change any of the arrangements they have in place for Tuesday.”
Head of Ofsted Amanda Spielman told BBC Radio 4’s Today programme: “We’re in a really difficult situation where people are having to weigh up short term concerns about health risks, and long term concerns about children’s education. It’s very difficult to do that.
“It’s so easy to call for closures and forget the long-term price which children pay which our visits show so clearly.
“We’ve had children yo-yoing in and out of school through the autumn and really suffering as a result. We need clarity, consistency, not last minute decisions,” she said.
In Basildon, Essex, students are being taught online. Last week saw schools there being allowed to close early after it recorded England’s third-highest Covid rate, with 433 cases per 100,000 people testing positive in the week to 5 December.
On Wednesday London is due to move into tier three restrictions.
Labour mayor of London Sadiq Kahn has called on secondary schools and colleges in the capital to shut early ahead of Christmas.
Mr Khan said: “If the government isn’t careful these children will pass on the virus to really vulnerable people because the rules are relaxed over Christmas.”
‘Too short notice’
On Monday, parents outside Robert Owen Nursery School and Christ Church Church of England Primary School, both in Greenwich, reacted to the news schools in the borough would be closing early.
One mother said: “It’s 2.5 days, so I don’t see what difference this is really going to make and I think the timing of it is really, really bad.
“I’m on maternity at the moment but if I was working, it’s just too short notice to get any kind of childcare arrangements in place.”
And a father added: “I think the timing might be right as a lot of people will be gathering for Christmas and it takes 10 to 14 days to show up so it may be damage limitation.
“I hope it will have an impact. If not, then it’s just political.”