A teacher in Chicago announced they would strike.

John Gress/Corbis via Getty Images

For the second time in seven years, Chicago public school teachers will strike starting Thursday, walking out of class, they say, in the name of better schools.

Gathered on the stage of a Union hall on Wednesday, the Chicago teachers Union said its delegates were in full support of moving forward with the strike. Delegates have already authorized the walkout and set a date to call off the strike.

“We have not achieved what we need to bring justice and high-quality schools to Chicago’s children and teachers,” said CTU President Jesse Sharkey. “We need to have the tools we need to get the job done in our schools. We need wages and benefits that will give us dignity and respect. We are on strike until then, until we can do better.”

In total, more than 30 thousand workers will go on pickets. This includes 7,500 teacher assistants, custodians, and security guards who are members of SEIU Local 73. SEIU said Wednesday night it has rejected the CPS contract offer and is scheduled to strike Thursday along with the CTU.

Officials say schools will be open, with principals and other administrators overseeing any children who need a place to go. They also tell parents that they can bring their children to libraries and some community organizations.

There are still approximately 300,000 students attending district schools. Another 62,000 students attending Charter and contract schools run by private organizations will not be affected.

Both sides say they will return to the negotiating table on Thursday, and will work toward reaching a deal.

Lightfoot announced Wednesday morning that it was canceling school Thursday in anticipation of a strike. She said she expected a strike, painting it as a strike of choice. She said there had been some progress at the negotiating table, saying: “at every turn, we have leaned back to meet the needs of the unions.”

“I was disappointed with the CTU’s decision to start work stoppages and force class cancellations because I feel like we rolled up our sleeves and negotiated in good faith for a long period of time,” she added Wednesday night. “We offered a historic package on the core issues of CTU compensation, staffing and class size.”

The Union has yet to accept the school district’s salary and benefits proposal, but the team talks without voicing serious objections to the mayor’s proposal for teachers that would provide 16% raises over five years and only minimally increase health care Contributions.

When it comes to salaries, it has focused on getting more money for veteran teachers and for office clerks and teacher assistants, known as PSRPs.

However, the Union’s most controversial requests are related to creating better working conditions for teachers and learning conditions for students.

The Union sees this as a moment to win the battles it has fought for years.

Since the current leadership took over the CTU in 2009, it has focused on social justice issues, going far beyond traditional bread-and-butter issues. The idea of using teacher contracts to promote so-called “common good” has gained traction across the country.

In 2012, the Union published a Manifesto entitled ” school Students deserve to be told in detail about the need for lower class sizes and more staff such as librarians, social workers and counsellors.

In the last two contracts, the Union raised these issues, but they also had to focus on protecting their members whose jobs were threatened by school closures and Charter school openings. The school district also has a budget deficit, making it difficult to argue for additional resources.

This year they saw an opening to try to win big on these social justice issues. The school district has more money after a change in the state’s funding formula and Lightfoot said she believes schools need more resources. The Union also believes it is necessary to make these demands after years of budget cuts that have led to staff losses in schools.

Many teachers say that the school environment is unacceptable.

Lightfoot and her team say they are determined to add another 250 nurses, 200 social workers and more special education case managers to schools. But they say putting those promises into the contract will limit their flexibility.

For months, Lightfoot has resisted putting compulsory class size caps, lowering class size limits and putting promises for more employees in contract. She also pointed out that state law prohibits teachers from striking on issues independent of wages and benefits.

Then, in recent days, the Union offered a compromise. They said lower class size and staffing increases could apply to schools in need in the first place.

And only on Monday, Lightfoot changed her position and signaled that she was willing to write into the contract some commitments on class size and staffing.

Speaking at a news conference Wednesday, Chicago Board of education President Miguel del Valle argued that the Union essentially got what it wanted. “They were concerned about staffing issues, they were concerned about class size,” he asked. “The mayor replied … what’s left?

But the Union argues that even this week, the school district’s proposals don’t do enough to meet their demands. They say they still want a nurse, librarian and social worker in every school. They also want to reduce the consultant’s workload.

The Union and the school district say some tentative agreements have been reached, but many unresolved issues remain.

The Union handed the school district 83 pages of demands on January 15. But negotiations did not begin in earnest until Lightfoot took office in may.

The Union’s contract expired on June 30.

Sarah Karp covers education for the WBE. Follow her on Twitter at @WBEZeducation and @sskedreporter.