Labour leader Sir Keir Starmer has accused Boris Johnson of ignoring an offer to help build public support for getting children back to school.
At Prime Minister’s Questions, Sir Keir said he wrote to the PM privately two weeks ago but had not received a reply.
Mr Johnson said he “took the trouble to ring” the Labour leader to brief him on lockdown easing measures.
He said Sir Keir’s “endless attacks” on the government were undermining “public trust and confidence”.
Sir Keir used PMQs to highlight what he said was a big fall in public confidence in the government’s handling of the coronavirus crisis, at a time when that support was needed most to ease the country out of lockdown.
From Monday, more than two million primary pupils in England were invited back to school, but heads reported “highly variable” levels of attendance, ranging from 40% to 70%.
The Labour leader told the PM: “I have supported the government openly and I’ve taken criticism for it, but, boy, he makes it difficult to support this government over the last two weeks.”
Mr Johnson accused Sir Keir of going back on his promise to work constructively with the government.
But Sir Keir said he had offered to help build consensus for the reopening of schools, in a letter, dated Monday 18 May, which the Labour Party has now published.
In it, Sir Keir tells the PM he supported the government’s “gradual easing” of lockdown but remained concerned about elements “including transparency, pace and having an effective test, track and trace system” and “the wholly unjustified attacks that have been made on teachers”.
The Labour leader tells the PM he supports the opening of schools “as soon as is feasibly possible”.
But he adds: “I am sure as prime minister you will share my concern that without a stronger consensus of professionals and parents behind the wider opening of schools, some parents will choose not to comply and the issue will become even more socially divisive.”
Sir Keir offered to meet Mr Johnson, along with Education Secretary Gavin Williamson and shadow education secretary Rebecca Long-Bailey to discuss how a “consensus can be achieved in the shortest possible timeframe” to get children back to school.
At PMQs, he said he had not received a reply to the letter.
The prime minister said he was surprised Sir Keir “should take that tone”, because he had replied by phone – and the Labour leader had “endorsed” the steps the government was taking.
“I think that he’s on firmer ground when he stands with the overwhelming majority of the British people who understand the very, very difficult circumstances that we are in,” he told Sir Keir.
The Labour leader then asked about the “promise” the PM made about having a “world beating” test, track and trace operation to be in place by 1 June, saying it was weeks away from being fully up and running.
Mr Johnson accused the Labour leader of “casting aspersions on the efforts of tens of thousands of people who set it up from a standing start”.
The Labour leader also criticised what he said was the government’s lack of transparency over the decision to ease the lockdown in England, asking the prime minister what the current Covid-19 alert level and R infection level was.
Mr Johnson slapped the despatch box as he replied: “He knows perfectly well that the alert level does allow it and he didn’t raise that issue with me when we had a conversation on the telephone.”
He said the alert level remained at four – but the government’s five tests for easing the lockdown had been fulfilled.
“The question for him is whether he actually supports the progress we’re making, because at the weekend he was backing it and now he is doing a U-turn, now he seems to be against the steps this country is taking,” added the PM.
Sir Keir also criticised Mr Johnson’s use of statistics, after the UK Statistics Authority said it had fallen “well short of expectations”., saying it was undermining trust.
Mr Johnson replied: “I really do not see the purpose in his endless attacks on public trust and confidence.”