In response to Emanuel's announcement, the Justice Department called the Chicago lawsuit "tragic". During a press conference, Emanuel accused the Sessions-led Department of "blackmailing" Chicago into changing its values.
"We are bringing this legal challenge because the rhetoric, the threats from this administration embodied in these new conditions imposed on unrelated public safety grants funds are breeding a culture and climate of fear", Emanuel's senior legal adviser, Corporation Counsel Ed Siskel, said on Monday. Chicago became the first city to sue the Justice Department over this issue.
Despite Chicago's sanctuary city status, the city's police are already allowed to share information with federal agents about undocumented immigrants who have prior felony convictions, pending felony prosecutions, or who are in the department's gang database.
Chicago's lawsuit will contend that the US government can not "commandeer local law enforcement to carry out federal immigration law functions", among other arguments, the city's top lawyer Ed Siskel said.
"If you let it stand, then it actually begins to not be challenged and this is one of many things that the Trump administration has been very clear that they've narrowed the focus, but this is the camel's nose under the tent", said Mayor Emanuel.
The dispute over sanctuary cities, where the local authorities limit their cooperation with federal immigration officials, pits two visions of public safety against each other. The city claims its "basic right to self government" grants it authority to direct local law enforcement not to work with federal immigration officers.
Top Senate Democrat urges Trump to block China deals over North Korea
It added that the U.S.is risking "adding kindling or, even worse, pouring oil on the flames". Tillerson , has turned up pressure on China to help isolate and cajole North Korea.
The lawsuit came almost two weeks after U.S. Attorney General Jeff Sessions said the Justice Department would bar cities from the Byrne program unless they allowed immigration authorities unlimited access to local jails and give the 48 hours pre-release notice.
Siskel also said the city chose to file a lawsuit now, rather than after it had been denied a grant, because of the new conditions set last week. Chicago is expected to receive $3.2 million this year for purchasing equipment.
The new rule would force local police to report about illegal immigrants released from police custody.
Sessions has repeatedly criticized Chicago for declaring itself a "sanctuary city", saying those policies tie the hands of law enforcement by "undermining federal laws that would remove criminal, illegal aliens from the streets and remove them from this country". The New York Times published a piece indicating that the executive branch does not have the power to cut funding from cities to enforce federal laws. Cook County, which also prohibits the Sheriff's Department from cooperating with immigration officers, is considering its "legal options going forward", Preckwinkle said.
Chicago argues the new conditions placed on the grant program "effectively federalize local detention facilities and violate the Fourth Amendment".