CHICAGO (WLS) -- Chicago Public Schools will not have class Monday as negotiations with the Chicago Teachers Union continue, the mayor and district officials announced Sunday night.
"Out of fairness and consideration for parents who need to prepare, classes will be canceled again Monday," she said. "Although we have been negotiating hard throughout the day, there has not been sufficient progress for us to predict a return to class tomorrow."
Monday will mark the fourth day classes have been canceled.
A small number of schools are planning to offer in-person activities for students, according to a letter sent out to CPS families Sunday night, adding that availability will depend on how many staff report to work to ensure student safety.
"While staffing levels at this time are outside the control of each school, principals can consider in-person opportunities if they meet minimum staffing levels," CPS CEO Pedro Martinez said in the letter.
District officials advise parents not to plan on sending their child to school on Monday unless their principal tells them that students can come for the in-person activities. They also said all schedule COVID-19 testing will continue at schools.
Some parents are left frustrated as they start another school week in limbo as negotiations wage on.
"Everybody else figured it out at larger school systems and Chicago is the laughing stock again.," said CPS parent Janet Luszczky.
The stalemate has kept CPS students out of the classrooms since Wednesday after teachers voted for remote learning, and there's still no deal over COVID-19 safety.
Luszczky, a mother of a 6th grade boy, said she's concerned about her son's education.
"I fear that he is slipping away from the momentum that he had in the beginning of the year," she said.
This comes after the union proposed Chicago teachers be in buildings this week, handing out digital devices and signing up students for COVID-19 testing in order to start remote learning on Wednesday -- with the goal of returning to in-person instruction on the 18.
Teachers said they want to be in school but believe CPS schools needs to ramp up testing like local private schools have. The Chicago Teachers Union held a press conference Saturday afternoon to discuss their latest proposal to the mayor's CPS team.
WATCH: CTU holds presser to unveil return-to-learning proposal on Saturday
The proposal requests that students begin remote learning on Jan. 12 before returning to in-person learning on Jan. 18, unless state or city health departments determine that conditions are not safe for in-person school at that time.
CTU's proposal also requests that CPS randomly test at least 10% of the student and staff population every week at every school. That program would allow students to opt-out. The proposal would also require CPS to pause in-person learning for 14 days and transition fully to remote instruction citywide if the COVID-19 test positivity rate in Chicago increases for seven consecutive days, remains at 15% higher than the rate from one week prior for each of those days and reaches 10% or greater on the seventh day.
CTU members also requested that any school with 25% or more of its staff out due to COVID-19 cases or exposures for two consecutive days will be transitioned to remote learning. For schools with 100 or more employees, a transition to remote learning will take place if those cases reach 20%.
They also introduced rules for remote learning if student exposures reach certain percentages. Elementary schools would transition to remote learning if more than 30% of students are instructed to quarantine or isolate. High schools and departmentalized middle school programs would go remote if more than 25% of the total student population had received such instruction.
While CPS agreed on some of the terms, even considering remote learning on a school-by-school basis, the proposal was ultimately rejected. Lightfoot and Martinez said they don't agree with CTU on delaying students' return to the classrooms, adding that they will "not relent."
"CTU leadership, you're not listening. The best, safest place for kids to be is in school. Students need to be back in person as soon as possible. That's what parents want. That's what the science supports. We will not relent," the statement said in part.
RELATED: Why are so many vaccinated people getting COVID-19 lately? | What you need to know
"Do you know the way teachers see that? We see that as bullying," said CTU President Jesse Sharkey. "We see this as an attempt to dictate all the terms and not listen to the people who are actually in there trying to make schools and make education work."
"If you ask me, kids want to be back in the classroom, and it's unfortunate. The parents are really scared," said fellow CPS parent Juan Alvarado.
A small group of parents hosted a virtual meeting Sunday night with the city's top doctor about their concerns on COVID safety in school. Dr. Allison Arwady said the data backs up a safe return for children, as city leaders will keep tracking potential outbreaks and continue their push for all students and staff to get vaccinated.
"What we have seen, over and over again, here in Chicago and across the country and around the world is that being in school does not make you more likely to be infected with COVID," Arwady said.
Still, the fight to return to in-person learning remains in a dead-lock.
"The Union wants to reassure the parents and guardians of Chicago that we will remain at the bargaining table until we reach an agreement that will return us all to in-person learning safely and equitably," CTU said in a statement Sunday.
The mayor appeared on "Meet The Press" Sunday morning, saying the ongoing talks are impacting students.
"This walkout by the teachers union, which is illegal, has had cascading negative ripple effects not only on the students and their learning, and their social and emotional welfare, but also on the families themselves," Lightfoot said.
On Friday, seven CPS families with students at 10 schools filed a lawsuit against CTU, accusing them of an illegal work stoppage. Some of those parents are unable to work from home, and some have children with special needs. Their attorney is seeking an injunction to force the teachers back into the schools, calling their job action illegal.
WATCH | CPS parents file lawsuit against teachers union
Despite the back-and-forth, teachers said they want to be in school. The union denied that anyone has stopped working and characterized this as a lockout.
"We are just simply asking, do what suburban schools, do what Catholic schools, do what private schools have done," CPS teacher Falin Johnson said. "They have tested, charter schools; they have tested those babies."
"Our teachers, our parents, our students, we all want to be safe in school," CTU organizer Linda Perales said. "The mayor can make that happen by stepping up and meeting out demands and ensuring safety."
CTU argues with COVID cases on the rise, keeping kids and staff inside school buildings is not safe.
RELATED: Plainfield school district cancels class Monday due to 'spiking number of bus drivers with COVID'
"When we came to school this Monday, I saw five times the number of students in quarantine," said CPS teacher Jackson Potter. "We saw staff members getting ill, we saw lower attendance. This wave was already making a large impact, and we weren't ready for it."
Both sides said they're committed to being at the bargaining table all weekend. CPS said it will have more to say about the status of Monday's classes, but already many principals are telling students not to show up.
As negotiations continue, the school district said it's working to finalize plans to get 350,000 rapid test kits from a company based in Abbott Park.