Mary Bousted, the joint general secretary of the National Education Union, said on Friday: “As keeping schools and colleges running with the least amount of disruption is a priority, making teachers a priority for lateral flow tests could be justified.

“Government also needs to address urgently putting in place measures such as ventilation, air filtration, mask wearing in secondary classrooms and isolation of very close contacts to ensure schools and colleges stand the best chance of limiting infection rates of staff and students.

“To refuse to act now will simply add to the disruption to education we have already seen take hold in many schools last term.”

Geoff Barton, the General Secretary of the Association of School and College Leaders, added: “Schools and colleges will do everything they possibly can to minimise the impact on pupils, as they always do, but there is a possibility that it may be necessary, where staff absence reaches unsustainable levels, to send home some classes and year groups to learn remotely for short periods of time.”