Vote Could Push Chicago Closer to Teachers Strike Angry that one promised raise disappeared and that they're being asked to work longer days without what they consider to be an adequate pay increase, Chicago teachers are considering authorizing their first strike in a quarter-century. In a signal of their mounting anger, teachers are voting this week - before a summer of negotiations and a recommendation from an independent fact-finder - on a strike that wouldn't happen until the next school year starts. If they do authorize a strike, teachers in the nation's third-largest school district would be leaving the final decision in the hands of union leaders. "This is a reflection of the treatment we as teachers have been subjected to this year ... that the posturing of the board of education has created such misery and suffering and discontent that we needed to send a message," said David Rose, a teacher at Roberto Clemente Community Academy. The frustration largely centers around Mayor Rahm Emanuel, who rescinded a 4 percent raise last year and then began pushing for a longer school day. Teachers say the mayor - and now the district - have not offered them enough money to make up for the added time. In this June 6, 2012 photo, Chicago Teachers Union President Karen Lewis casts her ballot during a strike authorization vote at a Chicago high school. Angered by Mayor Rahm Emanuel's call for a longer school day and wage and benefit concessions, 25,000 Chicago teachers voted this week to consider authorizing their first strike in a quarter-century. (AP Photo/M. Spencer Green) Close Chicago Public Schools has proposed a five-year deal that guarantees teachers a 2 percent pay raise in the first year and lengthens the school day by 10 percent. The union wants a two-year deal that reduces class size and calls for teachers to receive a 24 percent pay raise in the first year and a 5 percent pay raise in the second year. Under a new Illinois law, at least 75 percent of the district's 25,500 teachers would have to vote in favor of a strike authorization. But Rose and several other teachers said that amid the acrimony, they're not worried about the union reaching that threshold. The union is expected to release results next week. "I think it's going to be in the 90s because we are very angry," said Zulma Ortiz, a teacher at John F. Kennedy High School on the city's southwest side. We're fed up. For his part, Emanuel has said he thinks teachers do deserve a raise. He also said he believes the two sides can find "common ground" and urged teachers to wait for the fact-finder's report, which is due in mind-July and would offer recommendations for a contract. But Emanuel has had a contentious relationship with the Chicago Teachers Union since taking office last year and tried to go around the union in his push for longer school days. The union had turned down an offer for 2 percent pay raises in exchange for lengthening the school day, so Emanuel began asking teachers at individual schools to vote to waive the union contract and add the extra 90 minutes. The Illinois Educational Labor Relations Board subsequently voted to block Emanuel's administration from negotiating with more schools, but not before the mayor angered teachers. "He created an incentive for them, the causes and conditions for teachers to mobilize in a way they haven't mobilized before," said Robert Bruno, a professor of labor and employment relations at the University of Illinois at Chicago. Strike authorization votes by teachers are not all that unusual, according to experts, and most end with deals being hammered out before a strike happens. Teachers' strikes have become increasingly rare across the U.S., and the last in Chicago was in 1987.