• Unions have said they expect many schools to be closed on Thursday and large numbers of teachers - including about 75% in primary schools - to join the one-day strike.
• Teachers, parents and school administrators have struggled as new testing requirements were announced on the eve of the return from Christmas holidays and changed twice since.
French teachers walked off the job on Thursday over what they say is the government's failure to adopt a coherent policy for schools to manage the COVID-19 pandemic and properly protect pupils and staff against infection.
"We had reached such a level of exasperation, tiredness, and anger that we didn't have any other option but to organise a strike to send a strong message to the government," said Elisabeth Allain-Moreno, national secretary of the SE-UNSA teachers union.
Unions have said they expect many schools to be closed on Thursday and large numbers of teachers - including about 75% in primary schools - to join the one-day strike. Unions representing school directors, inspectors and other staff have also joined the strike.
The government, having reversed an earlier policy of quickly shutting down classes with positive coronavirus cases, has been standing by its policy to keep classes open as much as possible, saying some degree of complication is the price to pay.
"I know it's tough, but a strike does not solve problems. One does not strike against a virus," Education Minister Jean-Michel Blanquer told BFM TV.
Infections have surged in schools as France has set records with close to 370,000 new daily cases. Positive cases can result in dozens of pupils and staff being sent to labs and pharmacies for testing.
"The exhaustion and exasperation of the entire educational community have reached an unprecedented level," eleven unions said in a joint statement.
"The responsibility of the minister and the government in this chaotic situation is total because of incessant changes of footing, unworkable protocols and the lack of appropriate tools to guarantee (schools) can function properly."