District Judge Harry Leinenweber issued a nationwide preliminary injunction against the Department of Justice (DOJ) on Friday after Attorney General Jeff Sessions announced new rules governing DOJ law enforcement grants.
The city of Chicago sued the Trump administration last month over the DOJ's threat to withhold those grants from "sanctuary cities", which are cities that refuse to help federal authorities enforce immigration laws, reports The Hill magazine.
Leinenweber said in his 41-page ruling that Chicago had shown a "likelihood of success" in its arguments that Sessions exceeded his authority in July when he announced that the DOJ would withhold public safety grants to sanctuary cities.
The judge explained that he halted the DOJ policy nationwide because there is "no reason to think that the legal issues present in this case are restricted to Chicago or that the statutory authority given to the Attorney General would differ in another jurisdiction".
In July, the agency announced that a popular grant programme that provides money to local law enforcement for training and supplies would only apply "to cities and states that comply with federal law, allow federal immigration access to detention facilities, and provide 48 hours notice before they release an illegal alien wanted by federal authorities".
Sanctuary city is a broad term applied to jurisdictions with policies in place to limit cooperation or involvement with federal immigration actions, reports CNN.
Many US cities, counties and some states have a myriad of informal policies and laws that qualify as "sanctuary" positions.
The order said it would "strip federal grant money from the sanctuary states and cities that harbour illegal immigrants".