CTU President Karen Lewis said the union also was told another 1,000 members will get pink slips Friday.
News of the layoffs was first reported by DNAinfo.com Chicago.
Chicago Public Schools Officials later confirmed mass layoffs are coming, putting the number at 1,036 teachers and 1,077 support staff.
CTU said most of the cuts are veteran teachers, teacher assistants, clerks, technology coordinators, instructional aides, lunchroom workers and security guards.
Since May, CTU said, the district has removed more than 3,500 educators from their jobs. The mass layoffs are tied to citywide CPS budget cuts, dropping enrollment and the shuttering of 50 elementary schools.
The union, in a statement Friday morning, slammed Mayor Rahm Emanuel for the layoffs.
"It's unconscionable for a mayor who has found creative ways to create new bike lanes, a bike share program, lure white collar jobs and massive investment to the Loop and Gold Coast — but blames Springfield and teachers for CPS’s budget crisis— to lay off over 3,000 educators in the nation’s third-largest school district," the union said.
"This is the same politician who spent a year of his life calling for a longer school day who is allowing draconian budget cuts to undermine a better day for our students. That's a lack of leadership, a lack of creativity and a lack of political willingness to call upon his deep ties to the financial community to address the needs of children. The CEO and the mayor are making excuses, not improvements."
Lewis said layoff calls are going out Friday.
"We were told employees can expect calls from their principals early Friday," according to a statement from Lewis.
"Once again, CPS has lied to parents, employees and the public about keeping the new school-based budget cuts away from the classroom,” the statement charges.
Lewis said CPS plans to lay off more than 1,000 teachers, 451 paraprofessionals and 550 other employees "on top of the nearly 850 professionals who lost their positions in June and the 550 probationary appointed teachers [PATs] and 22 Title I teachers who were laid off in May."
"The loss of these workers will have a direct impact on the quality of instruction offered in our schools under the imposed 'longer school day.' These cuts are unnecessary and shameful for a system that prides itself on providing a high-quality education for our students," Lewis said.
CPS spokeswoman Kelley Quinn said in an email Thursday that layoff notices are “probably going to be tomorrow, but nothing is finalized.”
Quinn said Thursday that individual school budgets were still being reviewed, and final layoff numbers had not been determined.
“They still could change,” Quinn said in the email.
Last month more than 600 teachers were laid off as part of Mayor Rahm Emanuel’s school consolidation action, the largest in U.S. history.
Lewis said CPS continues to attack teachers.
"It is equally shameful that as CPS slashes school budgets, they have not offered one sound recommendation to resolve their 'budget crisis' other than attacking teachers, closing schools, disrupting communities and vilifying parents," the union president said.
"CPS can generate new revenue by closing corporate loopholes, engaging the banks about toxic swaps, re-examining the city’s TIF program and supporting a financial transaction tax which could put billions of dollars back into our schools. Once, again the most vulnerable children are going to receive the least. This will impact every single student in our district."
The school-closing layoffs will include teachers who will not follow students into receiving schools, a source said.
Over the last two weeks, most of the teachers affected by the layoffs have been notified by their principals, a source said.
“This also says much about the district’s much-touted, but poorly executed, 'Longer School Day,' program which they have recently branded as a 'fuller day'," Lewis said. "How can a 'full day' function without the appropriate staffing and funding levels and when schools lack books, toilet paper and other necessities? These cuts will surely increase class sizes. What we have now is the ‘empty day.’
“While the mayor is busy making multimillion dollar stadium deals, and the Illinois General Assembly is playing volleyball with workers’ lives, our students are the ones suffering," said Lewis.