Video report by ITV News Political Reporter Shehab Khan
Education Secretary Gavin Williamson stands firm on schools in England reopening on June 1 as it is based on the "best scientific advice".
Mr Williamson sought to reassure parents worried about children returning to school that the Government’s proposals are based on the "best scientific advice with children at the very heart of everything we do".
His comments come as teaching unions and ministers have been told to "stop squabbling" and work together to help reopen schools in England.
Mr Williamson also apologised to students and thanked them for their "sacrifices" during the coronavirus pandemic.
"I can only say how sorry I am that this has happened this year, he said before adding: "The sacrifices that you have had to make through no choice of your own."
When asked by ITV News' Political Reporter Shehab Khan about what the R rate of infection number would have to reach for the government to reconsider its reopening of schools from June 1, Mr Williamson said that scientists had been consulted before the models were developed.
England's Deputy Chief Medical Officer Dr Jenny Harries said the R number range published on Friday was 0.7 to 1.0.
She explained there are different R values in three areas - community, care homes and hospitals - and that any decisions on reversals would be down to ministers.
He added that there are children from difficult or very unhappy homes "for whom school is the happiest moment" in the week "and the safest place to be" and those children should be supported in their return to school.
"The longer schools are closed, the more children miss out" Mr Williamson said.
Lindsay said the reopening of schools was "very risky" given high rates of Covid-19, particularly in areas such as Gateshead where the R rate is currently highest.
Mr Williamson explained that the government will look at the R rate in great detail and schools "will only return if five tests have been met".
Responding to Mr Williamson’s comment at the briefing Patrick Roach, general secretary of the NASUWT teachers’ union, said in a statement: "The NASUWT welcomes the Secretary of State’s commitment to discuss a way forward which will help to ensure that schools can reopen safely to more children.
"It is urgently important that the Government takes every available opportunity to provide the necessary assurances that teachers are seeking."
He continued: "Schools are looking to the Government for clear and unequivocal guidance on the health and safety measures they will need to have in place prior to reopening.
"The bottom line is that no teacher or child should be expected to go into schools until it can be demonstrated that it is safe for them to do so."
The latest from the government briefing comes after a number of council in England have voiced their opposition to the reopening of schools.
Gateshead council leader described the move to bring pupils back to school as "madness" while others have vowed to defy central Government if schools are told to reopen.
Gateshead Council leader Martin Gannon said on Friday that his council’s advice continued to be to “stay at home”. He said his views on the lockdown were echoed by his counterparts in Newcastle and Sunderland.
Mr Gannon told the BBC: "The national advice telling us the lockdown is over is frankly madness to Gateshead."
Among the councils who are said to have concerns about reopening schools include:
Teachers have been backed by the doctors’ union – the British Medical Association – which said schools should not reopen until the numbers of coronavirus cases were “much lower”.
Coronavirus: Everything you need to know: