A federal judge has given the U.S. government 48 hours to explain its decision to deploy National Guard troops to Chicago, marking a tense standoff between federal and state authorities over the limits of emergency powers and the role of the military in domestic law enforcement.

The legal action began after Illinois officials filed a lawsuit seeking to stop the deployment of federalized National Guard troops to Chicago. The lawsuit was brought by Illinois Attorney General Kwame Raoul, joined by Governor J.B. Pritzker and Chicago Mayor Brandon Johnson. They claim the move violates state sovereignty and exceeds the president’s legal authority.

The federal order came Monday evening, when U.S. District Judge April Perry—appointed in 2022—directed government lawyers to submit a written justification by midnight Wednesday. A hearing is scheduled for Thursday afternoon, when both sides will argue whether the deployment should continue.

For now, Judge Perry has declined to issue an immediate restraining order, meaning the initial deployment is proceeding. Around 200 National Guard troops from Texas are expected to arrive in Chicago by Wednesday morning, assigned to assist in federal law enforcement operations targeting violent crime and illegal trafficking.