Chicago teachers to stage big rally amid hopes of end to strike CHICAGO (Reuters) - Thousands of striking Chicago teachers will march again on Saturday to keep the pressure on Mayor Rahm Emanuel to wrap up an agreement with their union so they can end a strike that has closed the nation's third largest school district for a week. The "Standing Strong with Chicago Teachers Rally" could be the largest demonstration against Emanuel's education reforms since the strike began in Chicago on September 10. Labor union supporters from neighboring states are expected to converge on Chicago to join many of the 29,000 union teachers and support staff in the march. Organizers said they hope the march will rival some of the massive rallies last year to protest against the efforts of Republican Governor Scott Walker in Wisconsin to curb the power of unions. The Wisconsin protests were unsuccessful but drew tens of thousands of government workers such as teachers. Emanuel angered the Chicago teachers by trying to ram through proposals to radically reform teacher performance evaluations and weaken job protection for teachers whose schools are closed or perform poorly academically. Led by a tough-talking former high school chemistry teacher, Karen Lewis, the union staged its first strike in 25 years, leaving 350,000 Chicago students with no school this week. Emanuel retreated from some of his proposed reforms, although details of what he has agreed with the union have not yet been released. Negotiators for the mayor and the union announced on Friday a tentative agreement that could lead to an end to the strike. But the union is wary of Emanuel, who has been called a "bully" and a "liar" by union leader Lewis, and the march on Saturday is intended to underline their resolve. If all goes well in the negotiations between Emanuel's Chicago School Board and the union this weekend, Lewis said that on Sunday she will ask some 800 union activists to suspend the strike and teachers will return to classrooms on Monday morning. They (union members) are very suspicious. You have to understand that we have been burnt by the (school) board in the past. You have to understand we want to make sure all our I's are dotted and T's are crossed," Lewis said at a press conference on Friday. The strike is the biggest U.S. labor dispute in a year and has galvanized the national labor movement. It also has shone a light on a fierce U.S. debate over how to reform struggling urban schools across the country. Both sides agree that Chicago public schools are not doing well. Students perform poorly on standardized tests of math and reading and the high school graduation rate is 60 percent compared with 75 percent nationally and more than 90 percent in some affluent Chicago suburban high schools. The union has railed against Chicago's unelected school board, which is stacked with representatives of business such as Penny Pritzker, an executive of Chicago's billionaire Pritzker conglomerate and a major fundraiser for U.S. President Barack Obama. They say the board is trying to privatize and corporatize the public school system. They have criticized Chicago's effort to open more publicly funded non-union charter schools, sometimes run by philanthropists, while some poor-performing traditional community public schools are being closed. The confrontation has exposed a rift within the Democratic party with many prominent mayors and politicians supporting Emanuel, a former White House chief of staff for Obama. But other Democrats have sided with the unions, which are major financial supporters of the party and are needed to help Obama in his reelection effort. Additional reporting by Mary Wisniewski; Editing by Louise Ireland