Labour has said it was “frustrating” that the Prime Minister had yet to respond to an offer of a meeting two weeks ago with party leader Sir Keir Starmer regarding school lockdown changes.

A row at Prime Minister’s Questions led to Labour choosing to publish Sir Keir’s letter to Boris Johnson, dated May 18, requesting a meeting with the PM and Education Secretary Gavin Williamson to come to a consensus for getting children back into schools.

In his letter, Sir Keir told the PM that reopening schools “requires a consensus and we are not there yet”.

The frustration is that we offered a meeting with the Government to talk about reopening schools safely and we didn’t get a response

At PMQs, Mr Johnson denied he had not replied, saying: “I am surprised (Sir Keir) should take that tone, since I took the trouble to ring him up, and we had a long conversation in which I briefed him about all the steps that we were taking. He did not offer any dissent at that stage.”

Labour said the phone call referred to by the Conservative Party leader was with all Opposition leaders.

Sir Keir’s spokesman, in a briefing with reporters, said the last one-to-one between the pair happened on April 29.

The Labour leader informed Mr Johnson in the Commons that he would put the letter “in the public domain, and the public can decide for themselves how constructive we are being”.

PMQs saw a number of similarly terse exchanges between the two leaders, with Mr Johnson accusing his rival of “casting aspersions” with comments about a lack of progress on a having a fully functioning test and trace system in place by the Government’s target date of June 1.

While a team of 25,000 manual tracers are at work, an NHS Covid-19 symptoms tracking app that was due to accompany their efforts is still being tested.

Labour has previously said schools should only return when test and trace was up and running.

A spokesman for Sir Keir said it was “right” that Labour challenged the Government when it thought changes to the lockdown, including ministers’ approach to schools, could have been made differently.

According to a poll by the National Education Union (NEU), two in five primary schools in England did not open to more children on Monday after school leaders and teaching unions expressed concerns about the safety of Reception, Year 1 and Year 6 pupils returning.

Asked whether Sir Keir was adopting a more aggressive approach following his line of questioning at PMQs, the spokesman said: “We are committed to acting as a constructive opposition and that means putting forward proposals for how we think we can support the national effort to stop the virus.

“However, constructive opposition also has to mean that the Government is willing to act constructively, and the frustration is that we offered a meeting with the Government to talk about reopening schools safely and we didn’t get a response.

“So it is right, in the national interest, that we raise concerns when we believe the Government isn’t doing the right thing and we work with the Government to put forward proposals for how they can do something different.”