CHICAGO — As the Chicago Teachers Union and the school district continued its showdown over classroom reopening plans and health and safety measures during the pandemic, the city blinked again late Wednesday and said it would continue remote learning as negotiations continued.

For a second day, the district canceled in-person learning for 3,200 prekindergarten and special-education students who had returned to classrooms three weeks earlier. Chicago Mayor Lori Lightfoot (D) said the district still intends to open schools Monday for its K-8 students.

“There are no easy choices,” Lightfoot previously said.

The union wants a memorandum of understanding added to its contract and an agreement to ensure a safe reopening, with staffers and teachers planning to continue remote instruction until a deal is reached.

Union leaders are contending that working conditions at schools are not safe and said they will trigger a strike if the district “retaliates” against teachers who refuse to show up in person by locking them out of teaching tools or docking pay.

Schools chief executive Janice Jackson has warned that if the union teachers refuse to come to school to teach in-person by Monday, the district will consider that an “illegal” strike.

Here’s what to know about Chicago’s push to reopen schools and the standoff that labor expert Robert Bruno of the University of Illinois calls “an exceptional and extraordinary situation.”

The two sides can’t agree on health metrics for reopening

The union has called for a health metric based on Centers for Disease Control and Prevention guidance, but the specifics of those metrics are still being debated between the district and the union.

The union has argued that city schools lack access to adequate testing and tracing programs; personal protective equipment; enough room ventilation and sanitization; and priority vaccination of educators and school support staffers. Additionally, it wants broader criteria for granting remote-work accommodations.

In response, the district said teachers working in the hardest-hit Zip codes would be prioritized for a vaccination, but Lightfoot said it would be unfair to prioritize all teachers over other essential workers.

Jackson said under its new proposal, the district has agreed to increase the amount of rapid coronavirus testing for school-based employees to twice a month and to begin offering free monthly coronavirus testing for students in the 10 Zip codes with the highest positivity rates.

Jackson said the district is now offering “clear guidance” on when a classroom, school or district should revert to online learning. The entire district may suspend in-person learning if the district positivity rate reaches 3 percent, “as established by our surveillance testing program,” Jackson said.

“We can’t guarantee a covid-free environment, but we can guarantee a strong plan in place that mitigates the spread of covid,” Jackson said earlier this week, noting the district has not had to close any facilities since prekindergarten and special-needs groups returned to classrooms on Jan. 11.

It’s unclear whether a strike would be legal

Experts say this is a gray area — and a pandemic that forced schools to shutter worldwide has created unprecedented safety concerns.

“This is uncharted territory,” said Mailee Smith, a staff attorney and director of labor policy at Illinois Policy, a conservative think tank. “We don’t have an example in the past of a union refusing to go to the school to work but being willing to work online. We don’t have an example of a school locking teachers out of their computers virtually when those teachers refuse to go to school.”

Smith said the novel situation probably means that Illinois Educational Labor Relations Board will have to weigh in to determine “who is right and who is wrong in the situation.”

Thad Goodchild, deputy general counsel for the Chicago Teachers Union, said the board has never definitively ruled on whether unfair-labor-practice strikes are recognized under the Illinois Educational Labor Relations Act.

“Chicago Public Schools is arguing that the only right we have to strike is in the event we are in negotiations for a new labor contract,” Goodchild said. “But unfair-labor-practice strikes are expressly recognized under the National Labor Relations Act.

A strike would probably mean more remote learning for students

Chicago Public Schools students have been learning remotely since the spring, with the exception of several thousand prekindergarten and special-needs students who opted to return to schools when in-person classes for that cohort resumed on Jan. 11.

Even those students who were briefly in school were learning remotely again as of Wednesday, with Lightfoot indicating that would remain the case until an agreement was struck.

If teachers hit the picket lines, students would continue with remote learning. The district has not discussed specifics of how it would address staffing in the event of a strike, but it has been experiencing a shortage of teachers and substitutes since before the pandemic.

Lightfoot contends that the learning losses due to being out of the classroom have fallen hardest on Black and Latino students from underserved neighborhoods, prompting her to “fear for their future.”

The union has noted that only 19 percent of eligible families in the first tier have opted to return to physical classrooms.

More than 80 percent of principals want to wait to reopen schools

An overwhelming majority of Chicago principals do not think schools should be open in January and February for in-person instruction, according to a survey of more than 370 principals and assistant principals released Wednesday.

Less than 17 percent of respondents said the district is prepared to open schools.

“Principals aren’t saying, ‘Let’s not open schools.’ They are saying that ‘we can’t open them in this district under this plan,’” said Troy LaRaviere, president of the Chicago Principals and Administrators Association. “Most principals want schools open, but we don’t believe they can be open under this district, under this leadership, this plan.”

LaRaviere said his questions to the district are met with documents that do not answer his questions, and he contends that “the district is letting things fall through the cracks” and “failing to do what they say they are going to do.”

The union and the city have a complex — and adversarial — history

On one side of the negotiation is the Chicago Teachers Union, more than 25,000 members strong and one of the most politically powerful unions in the United States. On the other is Lightfoot, who occupies one of the most powerful municipal executive positions in the country and wields significant influence over the nation’s third-largest school district. Chicago’s mayor handpicks the superintendent and the school board.

Meanwhile, the Chicago union has pushed to broaden what the collective-bargaining process should include, according to Bruno, director of the University of Illinois’ School of Labor and Employment Relations.

“CTU sees that process very expansively — it’s not necessarily such a radical idea,” Bruno said. “They make the case: ‘If it impacts our members’ lives and the employer has some control over it, we can bargain over it.’”

The union and the school district have clashed since the 1990s and even more frequently in recent years. If the union votes to strike in 2021, it will be its fourth in a decade.

The most recent strike, in 2019, went for 11 school days (for a total of 14). The union reached an agreement with Lightfoot that included reducing class sizes and hiring more social workers and school nurses.

The union also had a one-day strike in 2016 and went on a seven-day strike in 2012 for issues involving teacher pay and how staffers were evaluated and rehired after a school closure.

A historic public school shutdown in 2013 when the district closed 50 schools — 49 elementary schools and one high school — angered teachers and families and set the tenor for future negotiations.

Between 1969 and 1987, the union went on nine strikes. In 1995, Mayor Richard M. Daley tried to curb those union actions with Section 4.5 — a piece of legislation that limited issues the Chicago union could bargain or strike over.

Lightfoot campaigned on the repeal of Section 4.5 but reversed course once taking office, stating that a repeal “at this critical time would impair our efforts to reopen Chicago Public Schools and jeopardize our fiscal and educational gains.”

The Illinois General Assembly on Jan. 11 repealed Section 4.5. The measure has yet to be signed by Illinois Gov. J.B. Pritzker (D), who publicly supported the idea during his campaign.

The fight over school reopenings could have implications beyond Chicago

Labor experts were hesitant to make direct cause-and-effect connections between the outcome of Chicago’s school reopening fight and the path other cities may take, but the results will be closely watched.

“It would be hard to say that this portends any kind of sea change, but if CTU prevails, it certainly creates greater space for other teacher unions in urban environments to think about how they can bargain harder around health and safety,” Bruno said.

Bruno estimated that the district and the union may end up on the “cutting edge” of reopening plans despite their disagreements.

“They often fail to see the utility of what they’ve done because they’re usually yelling at each other, but they are carving out something that shows others how to thread the needle on an issue like safety,” Bruno said. “That can become a model for other large school districts.”