Schools minister Robin Walker would support reducing the coronavirus isolation period from seven days to five days if the science supported it.
Mr Walker said there had been “challenging levels of staff absence” in England’s schools this year as Omicron cases had spread, but he added they were “less” than had been projected.
His comments to MPs come after data published by the Department for Education (DfE) found that nearly 500 ex-teachers had signed up with supply agencies to help tackle staff shortages in schools.
The DfE has estimated that 8.6% of teachers and school leaders in England – around 44,000 of staff – were absent at the start of term last week.
Meanwhile, some 4.9% of teachers and school leaders were off school due to Covid-related reasons on January 6, up from 3.0% on December 16.
Mr Walker told the Commons Education Select Committee that he would support cutting the time people with Covid-19 had to spend in self-isolation if scientists recommended a reduction.
He said: “You’ll have seen all the debates about seven days versus five days etc. I think if the scientific advice shows that five days is safe, I would welcome a move in that direction.”
When asked whether schools would remain open for the remainder of the year, Mr Walker told MPs: “This is an absolute priority for us.”
He added: “We want to do everything we can to support schools to remain open.
“We have seen, of course, huge challenges and I’m extremely grateful to school leaders and teachers for the immense amount of work that they put in to keep schools open.
“What we’ve seen so far this year is some challenging levels of staff absence, but actually less, slightly less, than we have been projecting before the end of the year.”
But Labour MP Ian Mearns said the number of former teachers who had signed up to help with shortages was a “drop in the ocean” compared to the “tens of thousands” of staff absences in recent weeks.
Mr Walker said “staff absence is constantly changing and many of the staff who might be away this week may be back next week”.
His comments came after pupils began returning to class after the Christmas break, with new advice for secondary school and college students in England to wear face coverings in classrooms.
When challenged on the reintroduction of face masks during lessons, Mr Walker said: “It’s clearly not a cut-and-dried case to say in all cases masks are going to be the solution. It is something that shows, I think, that masks can make a difference in transmission.
“But where we are with the pandemic right now, and given the challenges of Omicron being a more highly transmissible variant, I think it is right to take every step that we can to reduce transmission especially when that might lead to children being out of school.”
The minister also defended the number of air purifiers being allocated to schools, adding that most classrooms were “actually well-ventilated”.
He said: “It’s not a case that there are 350,000 classrooms out there which are desperately in need of these devices and would benefit from them.”
Mr Walker added that providing a device to every classroom would be a “very poor use of taxpayers’ money” and it could also be “disruptive” for schools.
The minister said that exams taking place this month gave him “confidence” that GCSEs and A-levels would be able to go ahead in the summer.
Mr Walker told MPs: “We absolutely do want exams to go ahead, that is where we are focused on, and where things currently stand, we think they will go ahead, they should go ahead.”