Striking Chicago teachers and their supporters attend a rally at Union Park Saturday in Chicago. An estimated 25,000 people gathered in the park in a show of solidarity as negotiations on a labor contract continue.
The first Chicago teacher strike in 25 years entered its second week Monday, pushing students' earliest return to class to Wednesday.
Union delegates on Sunday deferred its vote to end the strike and asked for more time to review a proposed teachers' contract drafted last week by school officials and the Chicago Teachers Union. The decision prompted an angry Mayor Rahm Emanuel to file an injunction that could force the teachers back into class.
"I will not stand by while the children of Chicago are played as pawns in an internal dispute within a union," Emanuel said in a statement. "This was a strike of choice and now a delay of choice that is wrong for our children."
The mayor instructed the city's top lawyer to work with Chicago Public Schools' general counsel to file an injunction Monday asking a judge to immediately end the strike, now in Day 6.
In a statement, Emanuel called the strike illegal and said there's no reason why teachers can't return to work while the rest of the contract is ironed out.
"This continued action by union leadership is illegal on two grounds," he said. "It is over issues that are deemed by state law to be non-strikable, and it endangers the health and safety of our children."
But union president Karen Lewis said the deal isn't sitting well with many of the teachers.
"Our members are not happy, and they want to have the opportunity to talk to their members," Lewis said. "They want to know is there still anything more they can get."
The union delegates aren't scheduled to meet again until Tuesday, in part out of respect for for the Jewish holiday Rosh Hashanah, which began at sundown Sunday.
"If the agreement is not good, if the members reject it and think it won't improve conditions in their schools and classrooms, then we want the board to listen to those concerns before we would go back to school," CTU chief of staff Jackson Potter told NBC Chicago Monday.
School board president David Vitale said Monday the two sides are done negotiating and CPS is waiting on the union.
"We've done as much as we know how to do," Vitale said. "We reached an agreement with their leadership, we think it's a good agreement. It's time for the teachers to get back in school."
Potter said it's worth the wait.
"People have to live for three years under the terms of this agreement, and so it has to be a good agreement, it has to reflect the concerns that we brought to the table all along."
NBC Chicago has an array of reporters and producers covering the Chicago teacher strike. Check our live blog for continuous coverage and updates throughout the strike.