The reopening of schools should not be delayed any more than necessary, as teachers remain “determined” to get pupils safely back in the classroom, the Labour Party has said.

Term has now ended for schools in England until January and they will not be forced to remain shut in the new year, even in Tier 4 areas where coronavirus restrictions are toughest.

The Government has promised that a system of mass testing will be put in place by January to allow pupils to return to school in the new year.

But education sector bodies have criticised the plan – which was introduced to school leaders “at the 11th hour” – for its lack of detail on how the systems would be implemented.

Sam Henson, director of policy and information at the National Governance Association (NGA), said the responsibility for the systems put a “huge degree of pressure” on school leaders.

“What we’re going to end up with is headteachers and school leaders across the country working on Christmas Day and Boxing Day to put these plans in place,” he said.

Labour leader Sir Keir Starmer said that Boris Johnson needed to support teachers in implementing testing systems in schools.

“I don’t think the Prime Minister should be delaying schools coming back any more than they’re already delayed,” he told a press conference on Sunday.

“What we need is a plan for schools to come back safely and that involves mass testing.

“The Prime Minister has offered mass testing and now he’s got to deliver on it.”

Shadow foreign secretary Lisa Nandy said that little progress had been made on implementing the systems so far and that headteachers had been faced with an “impossible situation.

“Children need to be in school,” she told The Andrew Marr show.

“If we don’t have plans to get children safely back into school then some children will live with the consequences of that for the rest of their lives.

“(Teachers) just wish that they had a Government that was working with them rather than, as it feels like at the moment, like the Government is tripping them up at every turn.”

Ms Nandy added some children had missed up to 10 out of the last 13 weeks of education due to “continued bouts of self-isolation”.

Concern about reopening comes shortly after schools in London were threatened with legal action by the Government for attempting to move learning online.

The National Education Union (NEU) said its members have reacted “with fury” to the way the Government’s handling of the situation.

Kevin Courtney, joint general secretary of the NEU said: “It should fundamentally be a public health question but public health resources are not being deployed.

“Instead headteachers are presented at the last minute with inadequate and partial documentation, to be implemented on an impossible timescale, without the staff required to do it.

“It cannot and will not work this way.

“The Department for Education needs to seriously rethink its plans on testing and when schools should reopen in January.”

Professor Devi Sridhar, chairwoman of global public health at Edinburgh University, said that schools should be kept open “as much as possible” but suggested that a distinction should be made between student age groups.

She told Sky News’s Sophy Ridge On Sunday programme: “I think we need to divide kids under 12 which we know generally have not transmitted that well between each other, we haven’t seen many outbreaks in nurseries and primary schools, and secondary schools were children are very much like adults after age 12 and how we manage those.

“But schools need to be kept open as much as possible and the way to do that is to keep our community prevalence low so viruses never even enter the school in the first place.”

Health Secretary Matt Hancock refused to confirm that schools in Tier 4 areas would reopen in January if cases continue to rise.

“The Education Secretary (Gavin Williamson) has set out the plans for schools in January and because of testing and because we know the tests work on this new variant, we’ve got plans to keep the schools open that are essential in a way, that can stop them from transmitting the virus by using very extensive testing in schools,” he said, speaking to Sophy Ridge On Sunday.