Teachers at five charter and contract schools could walk out on their jobs by the end of the work day on Wednesday if a deal isn’t reached in bargaining sessions for a new contract.

Building on momentum from two successful strikes of charter networks, the Chicago Teachers Union announced that 134 educators from two Instituto del Progreso Latino schools, the Chicago High School for the Arts, Latino Youth High School and Youth Connection Leadership Academy could walk out Wednesday. Altogether, the strike could affect almost 1,800 students.

Related: Teachers union looks to a mediator after contract negotiations stall over district contract

In addition, instructors and adjunct faculty at Chicago’s city colleges have authorized a strike beginning the same day over slow-moving negotiations.

“We have been negotiating with management, and we have received no results,” said Linda Zaia, a teacher at Youth Connection Leadership Academy and secretary of the union’s charter division. “Their bottom line is dollars… not the students’ safety, not restorative justice, not maintaining quality education for your students through keeping quality educators long-term.”

Charter schools are publicly funded and privately operated schools. Contract schools are also privately run, but remain under the umbrella of Chicago Public Schools.

A strike at yet another charter cluster is pending: The union announced Thursday that 93% of its members at three schools owned and managed by Aspira, along with another school owned by Youth Connection Charter School but run by Aspira voted to authorize a strike, but they did not set a date.

At the five schools now facing a Wednesday strike deadline, teachers are seeking more resources for classrooms, a pay bump that would bring their wages closer to those of district-employed teachers, and better counseling and nursing support for students.

Educators at Instituto del Progreso Latino in particular are demanding that their schools comply with federal rules on teacher assistance for special education students and English language learners.

In a statement, Teri Argos, a spokesperson for the Institutio schools, said they had come to a tentative agreement on provisions for special education students and English language learners, sanctuary schools and grievance procedures. But the school’s management is “disappointed that the CTU has chosen to announce this strike while we are making progress at the negotiating table,” Argos said in a statement.

Talks haven’t yet settled economic provisions. Educators at the Instituto schools have at least three more bargaining sessions before the strike date.

If teachers walk out, it would be Chicago’s third teachers strike in four months. The city has been at the forefront of the charter labor movement. It was home to the first-ever charter teachers strike, at Acero schools in December, and a second one at four Chicago International Charter Schools in February.

For Mihir Garud, a a ninth-grade financial literacy teacher and treasurer of the Chicago Teachers Union charter division, the pending strike is part of larger union efforts to change conditions for teachers in the charter industry. “This is not the case of one bad operator or one bad employer, this is a systemic problem across the charter sector,” he said.

Garud and other charter teacher organizers belong to a union coordinating committee that makes recommendations on multiple contracts organized around several networks.

Meanwhile, the union is urging its 21,000 members at district-run schools to put aside money in anticipation of a potential strike at the start of next school year, part of a two-pronged strategy that the union hopes will change the education in Chicago. Teachers union President Jesse Sharkey told the City Club Thursday that the union is looking toward bringing in a mediator to move stalled negotiations forward.

The five charter and contract schools announcing the strike deadline represent only a small portion of the Chicago charter networks in negotiations. Nearly all are negotiating a new contract or a replacement for a previous contract that expired over the summer.