LONDON — British children are gearing up to return to school on Monday after a two-month closure, part of what Prime Minister Boris Johnson said was a plan to get the country to “start moving closer to a sense of normality.”

As part of the plan, millions of high school and college students coming back to U.K. classrooms will be tested for the first few weeks. Authorities want to quickly detect and isolate asymptomatic cases in order to avoid sending entire schools home.

“We are being cautious in our approach so that we do not undo the progress we have made so far,” Johnson said as he urged people to get vaccinated.

High schools and colleges can reopen in phases to allow for testing. The U.K. government has distributed nearly 57 million rapid “lateral flow” test kits to schools across the country, but there are concerns about the accuracy of the tests, which may result in pupils being forced to self-isolate unnecessarily.

But Susan Hopkins, a director at Public Health England, told the BBC on Sunday that evidence from testing over the past eight weeks suggested less than 1 in 1,000 tests resulted in a false positive.

Britain has had Europe's deadliest outbreak, with nearly 125,000 COVID-19 deaths.