DES MOINES, Iowa — Iowa Gov. Kim Reynolds insists the state controls how public schools will resume classes next month, saying districts can resort to online learning only if coronavirus cases are surging in their communities.

The teachers union immediately pushed back against Reynolds’ statement Thursday, saying that the lives of children and teachers are at stake and that science not politics should guide decisions.

The governor has said the state will require at least half of classes to be held in person. On Thursday, she updated that guidance to say the state will decide when K-12 schools can send students home based on community virus spread and student illnesses.

Reynolds’ rules for school makes exceptions for parents who can choose to keep a child at home for remote learning, and districts must make accommodations for any student to learn remotely if they, a caregiver, or a person they live with has a health condition that would increase their risk of COVID-19.