The strike led by the Snuipp-FSU union, the largest among primary school teachers, comes after the latest of several changes on testing and isolation requirements for potential Covid cases announced by Prime Minister Jean Castex late Monday.

After seeing long lines of parents outside pharmacies and labs in recent days to test children in classes where a case was detected, Castex said home tests could now be used to determine if a student could return to school.

But teachers say class disruptions have become unmanageable with the spread of the highly contagious Omicron coronavirus variant.

“Students cannot learn properly because attendance varies wildly, and a hybrid of in-house and distance learning is impossible to put in place,” the Snuipp-FSU said, adding that absent teachers are not being replaced.

It is also demanding the government provide facemasks for staff, including the more protective FFP2 masks, and CO2 monitors to check if classrooms are sufficiently ventilated.

“Not only does the current protocol not protect students, staff or their families, it has completely disorganised schools,” the union said, claiming that classes have effectively been turned into “daycare centres.”

Education Minister Jean-Michel Blanquer has said the government is doing everything possible to avoid outright school closures that could cause havoc for parents and jeopardise learning for thousands, especially those in low-income families.

“I know there is a lot of fatigue, of anxiety… but you don’t go on strike against a virus,” Blanquer told BFM television on Tuesday.

As of Monday some 10,000 classes had been shut nationwide because of Covid cases, representing around two percent of all primary school classes, Blanquer said.