Chicago Teachers Union members overwhelmingly have voted to authorize their leaders to call a strike, although a final decision on a walkout would be months away.
The union says 88% of eligible members who voted marked yes to authorize leaders to call a strike. The voting took place over three days from Dec. 9 to 11. State law says 75% of membership must approve strike authorization.
Union officials say March is likely the earliest teachers could walk off the job. CTU's contract expired over the summer. Both sides are getting help from a mediator, though talks haven't progressed. Chicago teachers went on strike in 2012.
Without help from state lawmakers, Chicago Mayor Rahm Emanuel's administration has said hundreds of teachers could be laid off.
