Mayor Rahm Emanueland Cook County Board President Toni Preckwinkle slammed the 5-4 U.S. Supreme Court decision in the Janus v. AFSCME Council 31 case, and criticized Gov. Bruce Rauner for celebrating a ruling the mayor called “an attack on working families.”

Union officials said they anticipated no changes to current negotiations.

No longer do government employees have to pay fees to the labor unions that represent them in contract negotiations. Those requirements violate workers’ First Amendment free-speech rights, according to the decision.

“I strongly disagree” with the court ruling, Emanuel said. “It is not a victory for taxpayers.”

Emanuel said about 900 of the city’s 33,000 workers pay fair-share fees to unions that represent them but to which they do not belong. Emanuel said he would only be “guessing” when asked how the city will implement the decision, which he noted was “hours old.”

However, Emanuel said he would continue to partner with the city’s 35 unions.

Preckwinkle also blasted the decision.

“This is the culmination of yet another partisan effort to weaken and undercut public employee unions,”  Preckwinkle said. “Janus was funded and supported by corporate interest groups that want to make it harder for workers to stand united, among them our own problematic governor. Collective bargaining remains an important part of the fabric of our country… I’ll continue to support unions and efforts they’re undertaking to protect working families.”

Approximately 82 percent of the county’s workforce belongs to a union or pays fair share fees.

At the county, fair share fees and union dues are withheld from employee paychecks by the comptroller and remitted to unions during the payroll process. Cook County will stop collecting fair share dues effective Wednesday, spokeswoman Becky Schlikerman said. Asked if the county will ask union members to opt-in to paying dues, as the state is reportedly doing, she said their legal department is reviewing the issue.

Velisha Haddox, the head of the county’s Bureau of Human Relations, said the decision would not effect ongoing collective bargaining negotiations. One third of the county’s labor agreements up for negotiation have been confirmed by the board.

“At this point, bargaining continues and we’re not anticipating any impact, but we continue to work with the unions to the extent they raise issues, new issues on the table that we need to help them resolve,” Haddox said.

Chicago Federation of Labor President Bob Reiter said he expected the city and county to begin complying with the ruling immediately.

The decision will likely not have an impact on future contract negotiations, Reiter said. Anders Lindall, a spokesman for AFSCME Council 31, agreed.

“We believe that both the city and the county understand the depth of labor’s collective strength in the Chicago, as well as the rest of the state,” Reiter said.

Several aldermen condemned the decision, which was announced just before the City Council’s June meeting.

Ald. George Cardenas (12) said unions had made it possible for thousands of Chicagoans to live middle-class lives. He pledged to fight the impact of the decisions, which could cost unions millions of dollars the groups have used to support candidates and campaign for issues such as a $15 minimum wage.

“Chicagoans, pull up your sleeves and get ready to fight for progress, equality and the American Dream, one union at a time,” Cardenas said.

Ald. Carlos Ramirez-Rosa (35) also struck a defiant tone.

“The labor movement is bigger than any right-wing court decision, bigger than any billionaire, or corporation,” Ramirez-Rosa said. “Our labor movement will never die because it is reborn every time a woman says no to sexual harassment in the workplace, every time a worker goes on strike, every time a worker demands dignity in the workplace and stands up for their rights.”

The City Council’s Progressive Caucus called the decision “radical.”

“We will always stand with the public employees keep our communities safe and healthy — and we will continue to defend workers’ right to organize, bargain collectively, and stand up to right wing attacks,” the group said in a statement.