Illinois Governor JB Pritzker has committed to challenging any move by Trump to send National Guard troops to Chicago in federal court.

Pritzker declared, “If the National Guard or other military personnel are deployed to Chicago, we will immediately file a lawsuit in court,” on Thursday.

Illinois Attorney General Kwame Raoul also stated that the state would probably oppose such a deployment in court, claiming it would likely be illegal and unconstitutional for Trump to proceed.

Raoul referred to the militia clause in the Constitution, explaining that “Congress holds the authority to decide how the National Guard is federalized,” not the President.

Trump invoked Title 10 of the U.S. Code for a June deployment of the National Guard to Los Angeles, a move a federal judge recently deemed illegal. This code permits the President to call upon “Federal service members and National Guard units from any state in numbers he deems necessary to halt an invasion, quell a rebellion, or enforce laws.”

Raoul argues that Chicago isn’t dealing with a “foreign invasion,” “rebellion,” or “inability to put in effect federal law.”

Raoul also mentioned the Posse Comitatus Act, which restricts the military from engaging in civilian law enforcement within the U.S., as previously reported.

“I’m not against federal resources coming to Chicago to fight crime, but let’s do it in a collaborative way,” Raoul concluded.