About 25,000 Chicago teachers are expected to go on strike Thursday, with the teachers union president saying he’s “overwhelmingly certain” the union’s governing body will vote down the city’s current proposals.

While some progress was made over the last few days of negotiations, it became clear Tuesday night that time would likely run out as the two sides remained apart on too many issues for a resolution to be reached before the union’s strike deadline.

“I have to tell the people of Chicago ... that we have not achieved enough in these negotiations to say we are done fighting,” Chicago Teachers Union president Jesse Sharkey said at a news conference Tuesday night at the union’s Near West Side headquarters.

Though the bargaining teams are set to go back to the table Wednesday morning to make a last-ditch effort to avoid a walkout, both sides had suggested that agreeable terms needed to be on the table by the end of Tuesday for any chance of getting a deal done in time.

That’s because union leadership is tossing the decision to the CTU’s House of Delegates, its elected body of hundreds of school-level representatives authorized to vote. Leaders said the delegates would need enough time to review the proposed contract language before voting up or down on the deal that’s on the table.

That vote is expected to take place late Wednesday afternoon with the results coming early in the evening. Sharkey said the teams will negotiate in the morning before stopping sometime in the afternoon ahead of the meeting. But he said the union’s bargaining team “cannot recommend postponing a strike” and would advise the delegates to turn down the deal, which he’s “overwhelmingly certain” they will do.

The move to lay the decision on the House of Delegates is a departure from the 2016 negotiations, when union leaders were the ones who decided an 11th hour deal just before a midnight strike deadline was good enough to call off the walkout. But back in 2012, it was the delegates who declined the city’s proposal and voted to go on with what ended up being a seven-day strike.

At the table, there were positive discussions held Tuesday on a few issues — including special education, class size and staffing of nurses, librarians and social workers. But negotiators on both sides of the table said not nearly enough progress was being made.

CTU bargaining team member Karen Soto said the two sides have “not gone anywhere” in terms of getting class size demands in writing. And though Mayor Lori Lightfoot said she’s willing to work out a deal on the union’s staffing and class size demands — a major shift from her stance the last several months when she said she wouldn’t agree to draft contract language on those issues — Sharkey said those promises haven’t turned into tangible progress at the table.

From the city’s perspective, the mayor has moved considerably off her opening offers, dropping a proposal that would have cut down on teachers’ preparation time and listening to teachers’ concerns on a slew of other issues.

For the mayor’s team, there simply remain too many open demands from the union that need resolutions before a deal can be made with not enough time to work out solutions, a source close to negotiations said. Unless there’s a “drastic” change in bargaining Wednesday morning, city negotiators are also expecting a strike.

At an afternoon press briefing at City Hall, Lightfoot said there isn’t “bickering and fighting” at the table, but she lamented that negotiations seemed to be dragging on more than she wanted.

“It’s a slow process,” Lightfoot said. “There needs to be more of a sense of urgency because time is running out.

“In both of these instances, whether it’s CTU or SEIU 73, there’s a deal to be had,” the mayor said, referring to another 7,500 school support staff and 2,500 Chicago Park District workers who are also negotiating separate deals and could walk out with teachers Thursday.

The mayor partly attributed the slow negotiations to the union having a bargaining team of over 40 people and taking hours at a time to discuss proposals amongst themselves. The mayor’s team showed up at bargaining at 9 a.m. Tuesday but waited three hours while the union’s team caucused, she said.

CPS parents, meanwhile, received a robocall Tuesday evening with a recorded message from schools chief Janice Jackson telling them some of their options if a strike happens.

Jackson said all CPS school buildings would remain open and serve breakfast, lunch and supper, but classes and all after school activities would be canceled.

She said normal services would not be available to kids with medical needs and special education students. Contract nurses would be available as needed.

Earlier at City Hall, parents, students and community leaders vowed to join teachers on the picket line if Lightfoot refuses to deliver the “educational equity” she promised as a candidate for mayor.

Young and old activists held a news conference outside the mayor’s office demanding that Lightfoot to put in writing the “enforceable caps on class size” and additional support staff she has promised at the bargaining table.

Catherine Henchek said when her son started kindergarten at CPS, she was told they “couldn’t give him his medication every day because there was only a nurse once a week.”

Similar shortages remain.

“They have a secretary having to give kids insulin shots because the nurse only comes in once a week,” said Henchek of Parents 4 Teachers.

“Parents don’t want a strike. They want their children in school. But, we want fully–funded schools. We want fully-staffed classrooms. We want enforceable class-size limits. So, we support this strike. Mayor Lightfoot, you campaigned on a lot of these issues. You need to put those campaign promises in writing,” Henchek said.

Jennifer Nava, a youth organizer for the Brighton Park Neighborhood Council and a senior at Kelly High School, said she “shouldn’t have to stand up here and demand a nurse or librarian” for her school or “battle with my peers for teachers’ assistants because there’s too many of us in a room clearly not meant for 30 students and an outmatched teacher.”

“I’ve been advocating for true investment in CPS since I was 12. I’m now 18 and still fighting. But I’m tired of begging and crying. I do not do desperate pleas or sorrow. I get angry,” she said.

Late in the afternoon, CTU members and community organizers with Grassroots Collab rallied outside the Fulton Market offices of developer Sterling Bay. They argued that TIF dollars given for mega-projects should be redirected for vital city services such as public education.