CNN  — 

Chicago teachers will be back in school Tuesday and students are scheduled to return to in-person learning on Wednesday after the Chicago Teachers Union house of delegates voted to end the teachers’ work action over Covid-19 mitigation measures, Mayor Lori Lightfoot said at a Monday night news conference.

Earlier, the union representing public school teachers had tweeted: “The Chicago Teachers Union House of Delegates has voted tonight to suspend the Union’s remote work action while rank-and-file membership votes on the proposed agreement.”

The Chicago Teachers Union said Monday night that it expects to open polls Tuesday for rank-and-file members to vote on the agreement.

“This agreement moves toward what they have been asking for for a long time even if it doesn’t get all the way that we think we should have,” CTU Chief of Staff Jen Johnson said.

This deal included agreement on the metrics involved for determining school closures, according to Lightfoot.

“What I can tell you in broad strokes, we reached an agreement on the metrics at a school base level for when we needed to convert a classroom or school to go remote. Not surprisingly, the component parts of that depend upon staff and/or student absences,” she said.

Union officials said at least two schools are at those threshold right now.

Johnson said coronavirus testing in schools in the country’s third-largest system will increase and it will ramp up to 10% of students in each school being tested each week.

According to the mayor, they have added “some layers” to enhance the testing in schools and they will be working with the union in engaging families to increase testing consents.

“That’s a critical part of it. We want to get to as high a number in testing consents as we possibly can. And we’re going to work jointly with the CTU to get that done,” she said.

Johnson also said the school district committed to providing more KN-95 masks.

She believes contact tracing will improve because schools will have a team where staff is paid to do the tracing.

More than 340,000 students had missed four days of classes since teachers voted to teach remotely and the school district responded by canceling classes.

The stalemate over Covid-19 measures exemplifies debates playing out across the country: When and how should students return to classrooms during the Omicron variant surge?

As of Friday, Chicago was averaging more than 5,200 new cases a day – a 16% increase over the prior week, according to the city health department’s Covid-19 tracker. The city’s Covid-19 test positivity rate had a daily average of 21.1%.

What other school districts are doing

Across the country, many school districts are still grappling with reopening after the holiday break.

In Atlanta and Cleveland, schools returned to in-person learning Monday after a week of remote learning.

But schools in Jefferson County, Kentucky, and Nashua, New Hampshire, were closed to students Monday because of staffing shortages.

Milwaukee students were supposed to return to classrooms Monday, but the school district decided to extend remote learning for another week.

In Baltimore, more than 50 public schools transitioned to virtual learning Monday because of staffing concerns and a rise in Covid-19 cases.

“Decisions are made based on having enough staff available to operate a school OR the ability to conduct COVID-19 testing,” Baltimore City Public Schools said in a written statement. No decision had been made as to when students can return to those classrooms.

In Philadelphia, 91 schools are teaching remotely this week after “Covid-related staffing challenges,” the school district said.

Los Angeles students are slated to return to classrooms Tuesday, and the school district is in the process of universal Covid-19 testing. So far, 50,000 new Covid-19 cases have been identified, and those students and staff members will have to stay home.

How the standoff began

Last Tuesday, the last day students were in classrooms, Chicago Public Schools reported 422 new Covid-19 cases among students and 271 new cases among adults – both record highs for the academic year.

That night, the Chicago Teachers Union voted to start teaching virtually. The union said inadequate Covid-19 testing and staffing contributed to unsafe school environments.

“All we are asking is that we would like our students to test negative before entering in the building,” teacher Briana Hambright-Hall said. “A two-week pause (of in-person learning) is not too much.”

In response to union’s vote to teach remotely, the school district canceled classes – reiterating its stance that children need to learn in classrooms.

CTU proposed resuming in-person teaching Tuesday, January 18, “unless (the Chicago Department of Public Health) or the State of Illinois determine that public health conditions are not safe for in-person school at the time.”

Over the weekend, Lightfoot and Martinez issued a joint statement saying union leaders were “not listening.”

“The best, safest place for kids to be is in school. Students need to be back in person as soon as possible,” the statement said. “That’s what parents want. That’s what the science supports. We will not relent.”

This isn’t the first time school has been canceled over an impasse between the teachers’ union and Lightfoot.

In 2019, the same year Lightfoot took office, more than 25,000 Chicago educators went on strike to demand more support staff, higher raises and limits on class sizes.

The 11-day strike ended when the city agreed to increase school staffing, including more school nurses and 209 more social worker positions – enough for one social worker at each school.

The deal also included more funding to reduce oversized K-12 classrooms and more funding for recruitment and training.

CNN’s Raja Razek, Steve Almasy, Elizabeth Stuart, David Shortell, Omar Jimenez, Keith Allen and Dakin Andone contributed to this report.