A second Chicago charter school strike could be on the horizon as teachers at Chicago International Charter School prepare to announce a strike date Thursday.

Last fall, 96 percent of Chicago International’s 138 unionized educators voted to authorize a strike if contract negotiations failed. Now, claiming little progress at the bargaining table, the union plans a mass gathering of teachers at a press conference to announce a strike date.

The announcement follows other high-profile teacher union actions. The nation’s first-ever strike of charter teachers, when some 500 union members at Acero charter schools in Chicago walked off for a week in December, reverberated across the country. And Los Angeles teachers out on their first strike in 30 years this week were joined on the picket lines by charter educators on Tuesday.

Charter International is the umbrella organization for 14 schools run by a handful of management companies. Educators and some paraprofessionals at four of those schools are unionized — one run by Chicago Quest and another three by Civitas Education Partners.

The union is demanding increased pay and benefits, smaller class sizes,  more staff for special education,, and a single contract covering all four schools. It also wants paraprofessionals, such as teachers aides, to join the bargaining team at the Civitas-managed school where they are not currently part of the union.

Kimberly Randle, an English teacher at Northtown Academy, told Chalkbeat last fall that chronic teacher turnover was leaving many of her sophomore English students unprepared to start the next school year.

“Our students are not being able to get the education that they deserve,” Randle said.

The union will announce its strike date at 7:15 a.m. Thursday at CICS Wrightwood Elementary School in the Ashburn neighborhood.