A former Ofsted boss has urged ministers to consider cancelling the six-week holidays to help struggling school pupils.
Sir Michael Wilshaw said “working in holiday periods” could help students catch up on work missed during lockdown closures.
It came as Boris Johnson was accused by the Lib Dems of “rushing to bring schools back to distract from his scandal-hit spin doctor-in-chief” – and despite concerns from parents, teachers and pupils.
The PM confirmed schools will open to some primary pupils on June 1, despite scientific advice calling for an effective track and trace strategy, which is not yet ready.
Only pupils in reception, year one and year six are due to return.
But Sir Michael, who led the regulator until 2016, warned re-closing schools after only six weeks back could further hinder vulnerable pupils.
He backed a phased restart from next Monday, warning the UK risks creating a “lost generation” due to the long closure – but blamed ministers for teaching unions’ opposition to the plan.
He said: “The Government should have spent the past three months preparing the ground well, holding meetings with teachers’ and parents’ associations and so on, to make sure all the facts are there.

“Parents need something to go on to make a balanced judgment and I’m not sure they’ve received that. If parents lack that confidence, they are not going to send them in.”
The PM accelerated the return of secondary pupils, saying yesterday: “We intend from June 15
for secondary schools to provide some contact for year 10 and 12 students to help them prepare for exams next year.”
Up to a quarter will attend at a time but full distancing “may not be possible”, he added, though there would be smaller classes, staggered breaks and extra cleaning.
At least 20 councils say they won’t let schools reopen on June 1, but insiders fear this could rise to 50.
Education Secretary Gavin Will-iamson said last month there was no plan to “run schools through summer”.
Public health exp- ert Prof Devi Sridhar, of Edinburgh University, urged ministers to be “completely honest about scientific uncertainty”, saying “we don’t know the degree” that children transmit coronavirus to adults.”
Unison found only 2% of school staff felt reassured by guidance on reopening. The National Education Union rejected the call to reopen.
The National Association of Head Teachers said it “will take the PM at his word” that schools will be all-owed “to react to local situations”.