By Brendan O'Brien
CHICAGO (Reuters) - Classes were canceled for about 300,000 students in Chicago for an eighth day on Monday as the teachers' union and public school district failed over the weekend to resolve a deadlock in contract talks over class sizes, support staff levels and pay.
Each side blamed the other for the impasse in the third-largest U.S. school district, where the strike began on Oct. 17, and the union, which represents the city's 25,000 teachers, has been without a contract since July 1.
The strike is the latest in a wave of work stoppages in U.S. school districts in which demands for school resources have superseded calls for higher salaries and benefits. In Chicago and elsewhere, teachers have emphasized the need to help underfunded schools, framing their demands as a call for social justice.
The strike in Chicago is the second longest in recent memory. A teachers strike in Union City, California, in June lasted three weeks.
The union wants smaller class sizes, more support staff, a contract that runs three years instead of five, and more paid prep-time for elementary school teachers.
Mayor Lori Lightfoot and Chicago Public Schools Chief Executive Janice Jackson blasted the Chicago Teachers Union in a joint news conference on Sunday for not accepting the school system's offer.
"We are enormously disappointed that CTU cannot simply take yes for an answer," Lightfoot said before listing the specifics on offer, including "a big, 16% raise for teachers."
She added, "At every turn we've met CTU's demands."
While picketing at a North Side elementary school on Monday, CTU's leadership responded to Lightfoot.
"Do you say yes to injustice? Do we say yes to inequity? Do we say yes to things that are half done?," CTU Vice President Stacy Davis Gates said.
The weekend saw some progress, however, as the union representing some school support staff made a tentative deal to end the strike, Lightfoot announced, covering custodians, security officers and bus aides.
But media, including the Chicago Sun Times, said late on Sunday that 7,500 members of the Service Employees International Union (SEIU) would not cross the CTU picket lines. The terms of the SEIU agreement were not immediately available.
On Friday, officials had been more optimistic for children to be back in school after the weekend, with the leader of the CTU saying he was hopeful the previous day's talks had given the path toward a settlement.
President Donald Trump plans to be in Chicago on Monday for a speech and fundraiser for a group of international police chiefs that is expected to draw thousands of protesters as well as supporters, Politico and other media said.
But it was unclear how the planned protests and picket lines of the striking teachers would affect traffic and police resources.
The strike is the first major test for Lightfoot, a political newcomer elected in April. She has said the district could not afford the union's full demands, estimating they would cost an extra $2.4 billion each year for an increase of more than 30% in the current $7.7 billion school budget.
(Reporting by Rich McKay in Atlanta; Additional reporting by Brendan O'Brien in Chicago; Editing by Clarence Fernandez and Paul Simao)