CHICAGO (Reuters) - The Chicago Teachers Union resumed "intense" negotiations on Saturday with the nation's third-largest school district to avert what would be the biggest U.S. labor strike in a year over Mayor Rahm Emanuel's demand for sweeping school reforms.
Some 29,000 teachers and support staff have threatened to strike on Monday, setting up an awkward confrontation between Emanuel, President Barack Obama's former top White House aide, and organized labor in the president's home city.
A protracted stoppage could sour relations between Obama's Democrats and national labor unions, who are among the biggest financial supporters of the Democratic Party and will be needed by the party to help get out the vote in the November 6 election.
Both sides in the dispute were tight-lipped as negotiators arrived at teachers' union headquarters in downtown Chicago on Saturday for what union president Karen Lewis had described as "intense" bargaining, which could last all weekend.
"I'm not going to go into details at this time," Jesse Sharkey, Chicago Teachers Union vice president, told a rally on Saturday afternoon. "There's always the possibility for the resolution of a strike, and that's what we're working for."
While Emanuel did not attend the talks, he and Lewis have clashed. She has accused him of being a bully and using profanity in private meetings.
When talks adjourned on Friday, the union described the latest offer from the school district as "totally unacceptable."
The union opened its strike headquarters on Saturday, where more than 100 teachers, students and parents rallied in support. Many wore red T-shirts sold by the union.
People at the rally shouted, "Teachers, yes! CPS, no," referring to Chicago Public Schools management. There was a barrage of honking from passing cars in support of the union.
"Teachers want to be in the classroom but we need to stand up for our rights," said Albert Delgado, a technology teacher at the Whittier School, where he has taught for 17 years.
At issue are teacher pay and school reforms such as tougher teacher evaluations that are the heart of the national debate on improving struggling urban schools.
Emanuel is offering a 2 percent pay increase annually over the next four years, while the union wants substantially more.
Both sides in Chicago agree the city's public schools need fixing. Chicago fourth-grade and eighth-grade students lag national averages in a key test of reading ability, according to the U.S. Department of Education. One union complaint is that class sizes are far too big.
"One of my teachers has 39 students in his classroom and that's unsafe," said Adam Heenan, a social studies teacher at Curie Metro High School.
Emanuel, who has a reputation as a tough negotiator, is demanding that teacher evaluations be tied with standardized test results, a move the union is resisting.
Only about 60 percent of high school students in Chicago graduate, compared with a national average of 75 percent and more than 90 percent in some affluent Chicago suburbs.
More than 80 percent of the 402,000 students in Chicago public schools qualify for free lunches because they are from low-income families.
Until Emanuel pushed through a longer school day this year, Chicago elementary school students received fewer hours of instruction a year than any of 30 major city school districts studied by the National Center on Time and Learning reform group.
The city has little room to sweeten the pot in the negotiations because the school district has already drained its budget reserves and levied the highest property tax allowed by law to finance schools.
It also faces a crushing burden of pensions promised to retiring teachers, and an independent watchdog has said the city can no longer afford to pay the benefits.
Major credit rating agencies have downgraded the Chicago Public Schools debt rating, meaning it may have to pay higher interest rates if it issues bonds.
"I can only say that the teachers I spoke with believe we will be on the picket line (on Monday)," teacher Delgado said.
Additional reporting by Michael Hirtzer; Editing by Peter Cooney