CHICAGO (AP) — Leaders of the Chicago Teachers Union agreed Monday to let thousands of union members vote on a proposed deal to get students back into classes, clearing another hurdle in the fight to reopen the nation’s third-largest school district amid the coronavirus pandemic.

However, the union’s house of delegates didn’t issue a recommendation on the proposal that calls for more teacher vaccinations and metrics allowing school closures when COVID-19 infections spike.

Union members will vote Tuesday. If they approve it, the first batch of Chicago Public Schools students are expected in classes on Thursday and others in K-8 gradually returning over the next few weeks for limited in-person learning. If they reject it, the possibility of teacher lockout or strikewill loom again. No plans have been set for high school students’ return.

Both sides have been negotiating for months over plans to gradually bring back students in the roughly 340,000-student district, something with which schools worldwide have grappled. The contentious issues in Chicago included vaccinations, metrics to gauge school infections and accommodations for teachers who have a family member more susceptible to coronavirus.

The fight intensified in recent weeks as union members defied orders to return to in-person classes and Mayor Lori Lightfoot urged an immediate deal and threatened to punish teachers. During the house of delegate’s Monday meeting, a majority of leaders also voted to show they have “no confidence” in the leadership of Lightfoot or the district.

Earlier in the day, Lightfoot acknowledged the difficulty of the talks.

“This has been a very tough process for everybody in the CPS ecosystem,” she told reporters during an unrelated news conference.

Union officials have argued CPS’ earlier plan didn’t do enough to keep teachers safe, even after the district spent about $100 million, including to buy air filters for classrooms and voluntary COVID-19 testing for teachers. CPS officials have said opening schools is safe and that remote learning isn’t working for all students, including many Black and Latino students who make up the majority of the district.

The union had said that if CPS locked out teachers, as the district has done previously, they would picket. Such a move would have cut off virtual learning for all students. The union last went on strike in 2019.

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