CHICAGO – It’s official, the Chicago Teachers Union is calling for Mayor Rahm Emanuel to resign.

The union’s House of Delegates “voted overwhelmingly” last Wednesday to endorse calls for Emanuel and Cook County State’s Attorney Anita Alvarez to resign over the police shooting of black 17-year-old Laquan McDonald, who was killed by a white police officer, the Chicago Tribune reports.

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It’s the first time the union has ever called for a sitting mayor’s resignation, according to In These Times.

“Whereas, the actions of both Mayor Rahm Emanuel and Cook County State’s Attorney Anita Alvarez impeded the criminal justice system, and in the process has led to the erosion of public trust and confidence in their leadership; and the only way to restore this trust is with their resignations…,” reads a copy of the CTU resolution posted to Twitter by Sarah Chambers, a CTU executive board member.

“Resolved, that the CTU support demands that Mayor Rahm Emanuel, and Cook County State’s Attorney Anita Alvarez resign immediately from public office for the unconscionable delay of their governmental institutions in addressing Laquan McDonald’s killing and other issues of excessive, unwarranted, unjustified, and lethal police force in the City of Chicago that has surfaced in the aftermath …”

The measure demands the creation of a democratically elected civilian police accountability council to review the Laquan McDonald case and oversee future police issues. It also seeks to ban military institutions from training Chicago Police, and expresses support for Illinois House Bill 4356, which create a means for recalling the mayor of Chicago.

The CTU’s announcement comes in the midst of heated protests calling for Emanuel to resign because many believe the mayor and Alvarez “delayed the release of (the police shooting) videos for their own political gains in order to secure victory in their 2015 re-election bids,” the resolution reads.

The video shows McDonald was shot 16 times by CPD officer Jason Van Dyke in October 2014, and appears to contradict initial police reports that the teen lunged at the officer with a knife. The city managed to suppress the footage for over a year while Emanuel and Alvarez sought re-election.

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CTU members in December voted to authorize a strike as union contract negotiations with Chicago Public Schools continue to drag on. The union is negotiating its first contract with the city since the CTU launched a strike in 2012 that ultimately got its members what they wanted in 2012.

But Chicago Public Schools financial problems have reached epic proportions, with credit rating services listing its bond rating at less than junk, leaving city officials to beg for a bailout from state lawmakers. Republican Gov. Bruce Rauner, meanwhile, continues to clash the Democrat controlled General Assembly over the state budget, with no relief in sight for Chicago schools.

Chambers told In These Times the union wants an elected police oversight board for the same reason it wants an elected school board: because CTU doesn’t trust Emanuel.

“As teachers, we don’t trust any committee Rahm appoints,” she said. “Without community members on these boards, there’s corruption. There’s no accountability – they’re all appointed by the mayor and just do what he says.”

She also said it’s the CTU’s responsibility to speak out about racism and police violence.

“An overwhelming majority of CPS students are black and brown children,” Chambers said. “Our students and their family members are the ones getting shot. So we can’t just sit back and ignore what’s happening.”

Adam Collins, spokesman for Emanuel, told the Chicago Tribune “the CTU organized against the mayor’s campaigns in 2011 and 2015, and (the resolution) is nothing more than a continuation of their long-standing political position.”