Janice Jackson says the CTU is trying to use negotiations to ‘solve all of the problems’ in Chicago.

Chicago Public Schools CEO Janice Jackson said Friday she remains “hopelessly optimistic” a teachers strike can be avoided, but the worst could happen if the Chicago Teachers Union insists on using contract talks to “solve all of the problems in Chicago.”

Mayor Lori Lightfoot has offered the teachers a 16% pay raise over five years to match the proposal by an independent fact-finder. She also offered to build into the school budget, the first phase of a five-year plan to add more support personnel.

The CTU won’t agree to the money until it gets the other items on what Jackson calls its “social justice bargaining” agenda.

That includes everything from affordable housing and a dramatic increase in “community schools” to enforceable caps on class size, mandatory hiring of support personnel written into the contract and more teacher preparation time with potential to shorten the elementary school day.

On Friday, Jackson pegged the cost of the union’s demands at $2.5 billion.

That’s a cost Jackson claimed CPS can’t afford, even though the school system is in far better financial shape than it was in 2012, thanks to the avalanche of state funding secured by former Mayor Rahm Emanuel.

“It seems like they’re trying to get everything in the contract. ... We have to do this in a way where we prioritize the things that, we know, matter the most,” Jackson said.

“We can’t solve all of the problems in Chicago through the” collective bargaining agreement,” she added. “I don’t think that’s appropriate.”

Jackson acknowledged the CTU’s demand for a nurse, a social worker and a case manager for special education in every school is a laudable goal. But it can’t be written in stone.

“We cannot codify everything through the contract. Once you put it in a contract, these become permissible items to strike over,” she said.

Jackson noted there is a nationwide nursing shortage and that nurses need to be certified to work in schools and be members of CTU.

“If we put this in the contract today, we’re gonna be held accountable to get this done when we know it’s gonna take a process and creativity to do that. No responsible manager would hamstring themselves” that way, she said.

The CTU was among vanquished mayoral challenger Toni Preckwinkle’s biggest backers and most generous campaign contributors.

Jackson acknowledged the union is pushing the envelope as a “first test” of a mayor the CTU did not support.

But she argued that a similar social justice agenda may well have produced a similar confrontation if Preckwinkle had won.

“We could possibly be in the same position because, some of the things that have been promised or … things they thought they would get if a different candidate had won are things that, once you get in and see everything that’s going on — some of those things can’t happen in a short period of time,” she said.

If the CTU is counting on Lightfoot to fold in a desperate attempt to avoid starting her term with a teachers strike, Jackson said they picked the wrong adversary.

“She is a very principled person. If people are looking for somebody who’s gonna make decisions based on politics and political agenda and optics, that’s not what they’re gonna get out of this mayor,” Jackson said.

“She believes she did the right thing. I do, too, by offering a comprehensive and fulsome offer up-front. And that’s the way she’s gonna operate. … That’s what people will learn through this process.”

Jackson is a former CPS student, teacher and principal. Her children attend Chicago Public Schools.

At a time when CPS is already hemorrhaging students, what she fears most is a strike that would only exacerbate that disturbing trend.

“We know that there is a mass exodus on the South and the West Side due to violence. ... We see fewer people immigrating — legally and illegally — to Chicago. And we see dramatically low birth rates,” she said.

“Stability matters. If we’re gonna stave off that dramatic trend, we’ve got to make sure that people who do live within the Chicago city limits, choose CPS and a big part of that is stability.”