ST. PETERSBURG, Fla.  — Florida’s power struggle over wearing masks in school to guard against coronavirus infections landed Monday before a judge considering a lawsuit that challenges Gov. Ron DeSantis’ order reserving the mask decision for parents.

The three-day hearing before Leon County Circuit Judge John C. Cooper pits pro-mask parents against the Republican governor and state education officials who say parents, not schools, should choose whether their children cover up inside schools.

The hearings come as the highly contagious delta variant causes a surge in cases, hospitalizations and deaths across Florida, where the school year is already being disrupted.

Some districts belatedly began requiring masks, as recommended by the U.S. Centers for Disease Control and Prevention and numerous medical organizations, after classroom exposures forced them to send thousands of students and hundreds of teachers and staff into isolation or quarantine.

At least seven school districts representing more than 1 million Florida students were defying the governor’s order as of Monday morning and others have scheduled votes soon on the issue. State education officials have vowed to financially punish districts that don’t comply with the order, contending they are violating state law unless they allow parents to opt-out their children for any reason.

Charles Dodson, a former judge representing the parents challenging the governor’s order, said in an opening statement that the delta variant affects children more than the previous virus strain and places them at greater risk in crowded schools.

“Because of the delta variant, our schools are not safe and secure unless everyone wears a mask,” Dodson said. “It is certainly an emergency.”

The Florida Constitution and state law give local school boards the authority to decide health and safety matters affecting their students, Dodson said. He asked the judge to block the DeSantis order.

“Each local school board, and only each local school board, should be able to decide in each district whether to make masks mandatory,” Dodson said.

A lawyer for the defendants — DeSantis, Education Commissioner Richard Corcoran, the state school board and education department — said the governor’s order comports with the state constitution and law, particularly the Parents Bill of Rights measure that took effect in July.

That law states that only parents and legal guardians can “direct the upbringing, education, health care, and mental health” of their child, attorney Michael Abel said.

Abel said the state’s experts will testify that requiring students to wear masks causes many harms — — speaking difficulty, mood changes, breathing issues and depression — while scientists disagree on their effectiveness against the coronavirus.

Citing state statistics from 2020 — before the delta variant swept across the U.S. — Abel said 40 of the 67 Florida school districts mandated masks, and yet still had positive virus tests for 48 of every 1,000 students. Districts without mask requirements had positive tests for 50 out of every 1,000 students.

“Mask mandates are unnecessary,” Abel said. “We will show that all of the state’s actions were consistent with the Florida Constitution and state statute.”

The mask issue has sparked heated debates at local school board meetings, with one side claiming that a ban on mandatory mask rules denies their children a safe education, and the other contending such requirements amount to government overreach and even tyranny.

Miami-Dade schools, the nation’s fourth-largest district, started classes on Monday for its 340,000 students with a strict mask mandate. Superintendent Alberto Carvalho said the district would wear any punishment the state doles out as a “badge of honor.”

“I know it (wearing masks) is an inconvenience but it is a necessity considering the explosive nature of COVID-19 transmission in our community,” Carvalho said.

The largest school district in Florida that hasn’t imposed a strict mask policy is Orange County, where parents and teachers protested outside the district headquarters on Monday demanding that Superintendent Barbara Jenkins and the board make masks mandatory.

Sarasota County implemented its new mandatory mask policy on Monday — much to the chagrin of some students. Masks were optional the first two weeks of classes, but outbreaks districtwide prompted the school board to impose a strict mandate. Only students who provide a doctor’s note will be excused, an opt-out mirrored by other districts with mask requirements.

“I’ve struggled with wearing a mask. I know a lot of my friends have, too,” Mya Mamazza, an 11th-grader, told the Sarasota Herald-Tribune outside school Monday. “I have asthma, so it’s really hard for me.”

She wants the district to offer online classes if masks are mandatory, so she won’t have to wear one.

This hearing is scheduled to end by Wednesday. It’s not immediately clear when Cooper will rule, but the judge has said he prefers to issue his decisions from the bench — and he acknowledged Monday that time is of the essence.

“I want everyone to have enough time, but I think we need to move as quickly as we can,” Cooper said.