CHICAGO — The Chicago Teachers Union voted to refuse in-person instruction Sunday and directed educators to work remotely starting Monday. The decision comes two weeks after the nation's third-largest school district called teachers and staff into classrooms and started to lock them out from remote work.

Chicago Public Schools chief executive Janice Jackson had said the action would constitute an illegal strike. “I want to be clear, if teachers refuse to come to work on Monday, that is a strike, that is not a lockout,” Jackson said Friday as the union polled its 25,000 members.

But in a statement on Sunday, she said the district has agreed to a request from union leadership to push back the return of K-8 teachers and staff from Monday to Wednesday this week. “We now agree on far more than we disagree, but our discussions remain ongoing, and additional time is needed to reach a resolution,” Jackson said.

The Chicago Teachers Union said it does not have any agreement with the district on any terms but will continue to negotiate. “Our collective power is our greatest strength,” Chicago Teachers Union President Jesse Sharkey said. “And this vote cements our intention to continue to stand together in unity to land an agreement that protects educators, students and all of our CPS families.”

The Chicago Teachers Union has gone on strike three times in the past decade, including a 14-day walkout in the fall of 2019.

The union contends a strike, over unfair labor practices, would start if the district retaliates by denying teachers online access to their classes, as it has done with more than 100 staff members who did not receive preapproved health accommodations when Chicago schools reopened this month. The city is requiring all teachers to work from school buildings, even if their students had all opted for remote learning.

“Every time we take any sort of collective action, Chicago Public Schools claims it’s illegal,” said Chicago Teachers Union attorney Thad Goodchild. “It’s practically a form letter at this point, so we’re not surprised.”

Chicago Teachers Union Vice President Stacy Davis Gates said: “The only person that can cause a stoppage is the mayor and her team at CPS if they lock our members out of Google meets. That’s it.”

Mailee Smith, staff attorney and director of labor policy at the Illinois Policy Institute, a nonprofit think tank, said it is a gray area because under Illinois labor law, teachers and staff cannot engage in a strike when there is a current collective bargaining agreement in place — as was reached under the last strike in 2019. “Ultimately, the labor board could decide this is an illegal strike,” Smith said. “If that’s the case, CTU can be fined and pay back the school district for the days, the school district can punish or discipline teachers under their discipline policy.”

The Illinois Educational Labor Relations Board has already denied two of the union’s previous requests to stop the district from reopening in January. That doesn’t bode well for the union if the district files a complaint with the labor board, Smith said.

“Unfortunately for teachers, they may not know whether or not this is a legal strike until after the labor board weighs in, after they’ve already committed one way or another,” Smith said.

Under the city’s tiered reopening plan, pre-K students and cluster students, who are diverse learners of all ages who need “moderate to intensive” support, were offered an in-person option starting Jan. 11, a week after teachers returned. Approximately 19 percent of those students — about 3,200 students — returned to in-person classes.

The school district is scheduled to bring back up to 70,000 kindergarten through eighth-grade students for in-person learning on Feb. 1.

Of the approximately 355,000 students who attend public schools in Chicago, most come from low-income households. Nearly 80 percent of students in the district are eligible for free or reduced-price lunches, live in substitute care, or come from families who received public aid in 2020, according to the Illinois State Board of Education.

The union contends that “the district is demanding that 80 percent of educators need to return for less than 20 percent of students.”

On Wednesday, the union’s governing body, an approximately 700-member House of Delegates, sent a resolution to its 25,000 members calling for a rejection of in-person learning until the union comes to an agreement on health and safety concerns with the school district. Members voted electronically Thursday through Saturday evening.

Some of the discontent stems from campaign promises made by Chicago Mayor Lori Lightfoot, a first-term mayor elected in April 2019, to create more affordable housing, break up segregation and institute other changes, including having an elected school board, said Robert Bruno, a professor and the director of labor and employment relations at the University of Illinois.

Although the Chicago Teachers Union backed Cook County Board of Commissioners President Toni Preckwinkle, who ran against Lightfoot, Bruno said, “if you look at what Lori campaigned on and put it right next to what the Chicago Teachers Union wanted to bargain, you wouldn’t know who was the union and who was the mayor.”

But once Lightfoot was elected, and the union and district began to bargain in 2019, “things went south,” he said. In October 2019, the Chicago Teachers Union redefined what it means to unionize, Bruno said, by including atypical requests such as affordable housing for its students and teachers in its strike.

Lightfoot also campaigned on removing a section of the Illinois Educational Labor Relations Act, called Section 4.5, that was passed in 1995 to specifically limit the Chicago Teachers Union’s bargaining power. But since taking office, Lightfoot has backpedaled, stating that a repeal “at this critical time would impair our efforts to reopen Chicago Public Schools and jeopardize our fiscal and educational gains.”

“Lori clearly thinks that the Chicago Teachers Union is out to get her politically,” Bruno said. “That they are out to undermine her leadership.”

Despite Lightfoot’s public requests, the Illinois General Assembly on Jan. 11 repealed Section 4.5, which needs to be signed by Illinois Gov. J.B. Pritzker, who publicly supported the idea during his campaign.

Jordan Abudayyeh, press secretary for Pritzker, said on Sunday that the General Assembly still needs to send the bill to the governor to be signed. “They have not sent the bill yet, so he can’t act on it,” Abudayyeh said.

Once the bill is signed, Bruno said, it “would appear to say, ‘Chicago Public School District, you’ve got to bargain everything and everything is strike-able.’ ”

Smith contends that even if the bill is signed, the Illinois Educational Labor Relations Board, which is appointed by the governor, could still decide the strike is illegal.

“Under the current law, it already says that the parties are obligated to bargain wages, hours and working conditions. It’s not clear where safety fits into that,” said Bruno. “That provision makes it clear you can strike over what you can bargain for. So can you strike over safety? I don’t know.”

Jon Shelton, a professor of democracy and justice studies at the University of Wisconsin at Green Bay who is a labor historian, said that school districts and unions around the country are watching what is happening in Chicago.

“The Chicago Teachers Union has established itself as probably the most militant teachers union in the country, both in advocating for its members and their working conditions but also the community at large,” Shelton said. “A lot of eyes are on this. This has become so politicized because people really feel like their lives are on the line.”