UPDATE 1-Chicago teachers, mayor trade blame as strike extends into 11th day

The Chicago teachers union and Mayor Lori Lightfoot lashed out at one another over who was to blame as a strike that caused 300,000 public school students to miss classes extended into an 11th day on Thursday, despite a tentative contract deal. The two sides were at loggerheads over whether additional days would be added to the school calendar to make up for lost classes and whether the city's 25,000 teachers would be compensated for pay lost during the second-longest teachers' strike in recent U.S. history.

"Our members are tired, frustrated and miss their students ... we want to return to the classroom," Chicago Teachers Union President Jesse Sharkey said in a statement on Thursday. "By not restoring days of instruction to our students lost during the strike, the mayor is making it clear that she is more concerned about politics than the well-being of students." Lightfoot, a first-term Democrat, has rejected the demand for makeup days and accused the union of reneging on a deal reached Wednesday with the third-largest U.S. school district.

"We've given them a historic deal by any measure," Lightfoot told reporters late Wednesday. "The fact that our children aren't back in school tomorrow is on them." She added: "I'm not compensating for days they were out on strike."

Union leaders called on rank-and-file members to rally on Thursday morning to press for their outstanding demand. The terms of the proposed settlement were not disclosed. But some union leaders initially voiced enthusiasm for it.

"The CTU may have reached a monumental agreement," union Vice President Stacy Davis Gates said earlier on Twitter, referring to the tentative deal. The Chicago walkout follows a wave of teacher strikes across the country over wages and education funding during the past two years, including a week-long work stoppage in Los Angeles in January. African-Americans and Hispanics account for the majority of Chicago's public school enrollment.

As was the case in Los Angeles, the labor dispute in Chicago centered on a pay as well as teacher demands for contract language to reduce class size and increase staffing levels for support professionals, including nurses and social workers. Any settlement is subject to approval by the union's House of Delegates, a body consisting of 825 elected representatives from each of the city's schools and support staff classifications before classes can resume.

The district had said it was looking into whether it could make up more than eight school days lost during a strike, and the Chicago Board of Education would need to vote on adding any attendance days to the school calendar. The teachers' last contract expired on July 1, and they walked off the job Oct. 17.

The union was seeking a contract that runs three years instead of five and includes more paid preparation time for elementary school teachers. Lightfoot has said the union's full demands if met, would require an annual spending increase of 30% beyond the current school budget of $7.7 billion.