The move by Illinois Gov. Bruce Rauner to eliminate union dues is "unconstitutional," AFL-CIO President Richard Trumka told CNBC on Tuesday.
On Monday, Rauner announced an executive order eliminating dues for some state employees who do not want to pay to support union activities.
"He's saying he wants to have people that don't pay for the services they get," Trumka said in an interview with "Closing Bell."
"They get a collective bargaining agreement and all the benefits under it and he says they don't have to pay for it. What he's doing is actually unconstitutional."
The governor based his decision on a U.S. Supreme Court decision that found Illinois law violated the First Amendment by forcing home health-care aides to involuntarily pay union fees.
Trumka likened it to citizens paying taxes even though they may not agree with what Rauner is doing.
"I'm a taxpayer in Illinois. He's doing stuff to lower my wages and I don't want my wages lowered. Should I be able to withhold my taxes from him? Isn't that my First Amendment right as well?"
Rauner's officer did not immediately respond to a request for comment from CNBC.