Groups of pupils should only be sent home if there has been a positive test,
rather than someone just developing symptoms, the prime minister has said.
Boris Johnson said it was important for teachers and parents to examine the Public Health England guidance about testing.
Speaking to MPs on the Liaison Committee, he reiterated government policy by saying: “The reasons for sending such a class home, or a bubble home, would be if somebody tests positive.”
It comes as a teaching union leader warned that schools are struggling to cope with a lack of COVID-19 tests for pupils and staff as the situation is becoming “increasingly out of control”.
Dr Patrick Roach, general secretary of the NASUWT teaching union, has called on the government to prioritise the education sector for the allocation of tests in light of widespread challenges.
And the Association of School and College Leaders (ASCL) said it has received 264 responses from schools and colleges in recent days where leaders have said they have symptomatic staff and/or pupils who were struggling to access tests.
Mr Johnson admitted demand for tests in England has “massively accelerated” in the last two weeks, and daily coronavirus testing capacity will reach 500,000 by the end of October.
He said many people are using tests so they can resume normal life.
The PM also told MPs that the government will “very shortly” be setting out “the priority of the groups that we think should have tests”.
He added: “In schools, it’s very important that parents and teachers should look at the guidance about when you should get a test.”
Justice Secretary Robert Buckland has told Sky News’ Kay Burley that schoolchildren and their parents could be prioritised for coronavirus tests – after hospitals and care homes – as the government deals with “real challenges” in the system.
The government has come under growing pressure over a lack of availability of tests in some areas – blamed on problems with laboratory capacity – and admitted it could take a “matter of weeks” to solve the issues.
Currently anyone who displays coronavirus symptoms can get an NHS test, as well as those who have been asked to get a test by a hospital or local council.
Asked about targets to get tests to 10 million per day, Mr Johnson said: “I don’t recognise the figure that you have just given.
“But what I can tell you is that… there is an opportunity to do something that is wholly separate from the expansion of NHS Test and Trace, and that’s to see if we can get to a world in which there is a test and release system, as it were.”
The UK has recorded 20 more deaths of people with confirmed cases of COVID-19, according to government figures.
There were 3,991 new daily confirmed cases of coronavirus, compared with 3,105 on Tuesday, the figures show.
That means there have been 41,684 deaths in total, according to the official numbers.