Illinois Attorney General Lisa Madigan moved Monday to dismiss a federal lawsuit Gov. Bruce Rauner authorized that challenges “fair share” fees collected by labor unions in the state. Madigan also filed to intervene in the federal action, saying she would defend the constitutionality of Illinois’ law.

The law allows unions to collect the fees even from people who are not union members under the theory that they benefit from collective-bargaining agreements.

“I have submitted a motion to dismiss the case, arguing that the governor does not have the legal authority . . . to challenge the law in federal court,” Madigan said in a statement. “As attorney general, it is my job to represent the state and defend our laws when their constitutionality is challenged in court. Because the governor’s case questions the validity of the Illinois Public Labor Relations Act, I moved to intervene to provide the court with arguments regarding the law’s constitutionality.”

In February, Rauner issued an executive order banning the collection of fair-share fees. Anticipating a legal challenge, he simultaneously filed a lawsuit against two dozen unions and brought in an outside law firm to handle the case pro bono. Illinois labor last week filed a lawsuit in Illinois courts challenging Rauner’s executive order.

“As expected, the attorney general filed a motion in federal court to defend so-called ‘fair share’ union dues in state government, which is why the governor pro-actively asked the attorney general’s office to allow the governor’s office to use pro bono outside counsel,” the governor’s office said in a statement. “The attorney general’s actions will have no impact on the governor’s efforts to protect taxpayers and state employees who don’t want to pay forced union dues.”