By Juan Perez Jr. and Grace Wong

The Chicago Teachers Union on Monday delivered the city a message that union leaders have threatened for weeks: Educators are prepared to walk off the job for the second time since 2012 if an agreement can't be reached on a new contract.

The union said 88 percent of its 24,752 eligible members voted "Yes" to authorize union leaders to call a strike, well above the 75 percent threshold necessary for a strike to occur. Members voted in schools citywide over three days, and votes were tallied at the union's Merchandise Mart offices.

"Do not cut the schools anymore. Do not make the layoffs that you have threatened. Instead, respect educators and give us the tools we need to do our jobs," said Chicago Teachers Union Vice President Jesse Sharkey.

The vote gives CTU President Karen Lewis and other officials the OK to brandish the biggest weapon the union has in negotiations with the Chicago Board of Education. But the steps that must be taken before a strike could occur mean that Chicago Public Schools classrooms are not likely to shut down soon.

Over the past several weeks, the union exhorted its members to vote yes on a strike authorization vote, busing thousands of red-shirted teachers downtown for a rally in Grant Park late last month and promoting the vote on social media.

State law requires 75 percent of total union membership to vote for authorizing a strike. The 2011 law containing that provision was designed to tamp down the possibilities of a strike. But in 2012, nearly 90 percent of CTU members in June authorized union leaders to call a strike, leading to a seven-day walkout that September.

The contract reached following the 2012 strike expired June 30, and the two sides have been negotiating for more than a year, yet remain far apart on a number of issues.

The district says the union's demands would cost well over $1 billion a year, and require hiring more than 1,000 new school nurses, psychologists and social workers; hundreds of counselors and case managers. Union demands also include a 3 percent salary increase and pay for snow days.

CPS has said it would have to hire more than 5,000 teachers to accommodate a union demand to shrink classroom sizes.

Union officials say the district has asked for a contract that would amount to $653 million in cuts. Broad layoffs already are threatened by the district for early next year because of the district's latest financial crisis.

School board negotiators have also rejected CTU's demand to move talks to a final stage called fact-finding. That prompted the union last week to file an unfair labor practice claim with the Illinois Educational Relations Board.

The two sides enlisted a mediator's help this summer and the district wants that process to continue before a move to fact-finding. A fact-finding panel would be made up by a representative from each side and a neutral party.

Talks this time around have taken place mostly without much of the rancor that marked 2012 negotiations, when Lewis made it her mission to take on Mayor Rahm Emanuel after he took office with promises to make changes the union found unpalatable.

Lewis, whose potential bid to challenge Emanuel in his re-election bid was derailed when she was diagnosed with brain cancer just more than a year ago, did muster some of her old combativeness in the Grant Park rally about three weeks ago.

"Now it's time for us to act. We've been here before," Lewis told the crowd at Petrillo Music Shell. "No teacher wants to go on strike. We prefer to be in front of our students. But we know that when we must, we will withhold our labor."

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