In a show of solidarity, some janitors may be joining Chicago teachers on the picket lines.

Tom Balanoff, president of SEIU Local 1, says many of the 1,500 janitors who work in Chicago public schools have wanted to join striking teachers. Balanoff says he’s now filed a notice that could make that possible.

“On Friday, there very well may be Local 1 members—janitors—who will stand outside and support the teachers instead of go to work.”

Balanoff was among more than a dozen union leaders, representing everyone from nurses to electricians to police, who voiced support for striking teachers yesterday. State and national teachers union officials were there as well, including Randi Weingarten, the president of the American Federation of Teachers, the parent union of the Chicago Teachers Union. They spoke outside Chicago Public Schools headquarters.

Robert Kelly is head of the CTA rail workers’ union.

“Although our teachers are not in the classroom today teaching, they stand here today teaching all of us what is right when they fight for what is right—what is theirs!”

The leaders said the labor movement had to fight to get free public education for every child, and now has to fight to protect it.