Updated 6:30 p.m.

Mayor Rahm Emanuel’s administration filed a federal lawsuit against U.S. Attorney General Jeff Sessions on Monday morning to defend its status as a so-called sanctuary city for undocumented immigrants.

Sanctuary status means, in part, local law enforcement won’t give federal officials undocumented immigrants in their custody, except in certain criminal cases.

Last month, the U.S. Department of Justice said it would withhold millions of dollars of grant money from sanctuary cities. Sessions said grant applicants have to share information about undocumented immigrants to federal officials if they want the funding.

• RELATED STORY

Trump Unveils Legislation Limiting Legal Immigration

read more

But the lawsuit claims the conditions imposed by the Justice Department on the Edward Byrne Memorial Justice Assistance Grant are unlawful and unconstitutional.

“These new conditions — which would give federal officials the power to enter city facilities and interrogate arrestees at will and would force the city to detain individuals longer than justified by probable cause, solely to permit federal officials to investigate their immigration status — are unauthorized and unconstitutional,” the lawsuit stated.

Chicago last fall was awarded about $3.2 million from that grant for 2017, which is a sliver of the city’s $9.8 billion annual budget. Emanuel called Sessions’ conditions “precedent setting policy” that could extend to other federal grants.

Ed Siskel, a lawyer representing the city, said on Sunday that the lawsuit will argue that Sessions and U.S. Department of Justice  officials “cannot commandeer local law enforcement to carry out federal immigration law functions.”

The city plans to seek a preliminary injunction and wants a ruling to be made before September 5, when applications for the Byrne grant are due, Siskel said.

The city is using outside legal counsel from two firms — Wilmer Hale in Washington, D.C. and Riley Safer Holmes & Cancila in Chicago — but both are working pro bono, Siskel said.

“We don’t anticipate it will cost the city any additional resources to pursue this litigation,” Siskel said.

In an emailed statement Monday morning, Justice Department spokesman Devin O’Malley slammed the Emanuel administration for filing the suit.

“In 2016, more Chicagoans were murdered than in New York City and Los Angeles combined,” O’Malley wrote. “So it’s especially tragic that the mayor is less concerned with that staggering figure than he is spending time and taxpayer money protecting criminal aliens and putting Chicago’s law enforcement at greater risk.”

Federal law requires that Chicago files a single Byrne grant application on behalf of itself and surrounding municipalities, including Cook County and suburban Bellwood, Calumet, Chicago Heights, Cicero, Dolton, Evanston, Harvey, Maywood, Riverdale and Skokie.

That means that Sessions’ threat to withhold federal funding could have impacts beyond the city.

Cook County Board President Toni Preckwinkle issued a statement in support of the city’s lawsuit on Sunday. 

“I commend the Mayor and City for bringing this case to court, and we will assess our own legal options going forward,” Preckwinkle said in the statement. 

Bellwood Mayor Andre Harvey said his village supports the lawsuit, but he has no plans to take any legal action. He said Bellwood is not a sanctuary city and is frustrated that the new Justice Department conditions could hurt his police department’s bottom line. 

In the past, Bellwood has gotten about $10,000 from Chicago’s Byrne grant award, which Harvey said is used to buy police cars, bulletproof vests and other police equipment.

“If this passes and the Justice Department is able to do this, it’s simply opening up Pandora’s box. What will be next?” Harvey said.

Chicago Ald. Carlos Ramirez-Rosa (34th Ward) said the lawsuit is a step in the right direction. But he said the city’s own sanctuary ordinance does not do enough to protect people’s Fourth Amendment rights. 

“The mayor’s been facing pressure from community groups, from the ACLU, to take local action, to strengthen our sanctuary city policy,” Ramirez-Rosa said. “It’s hypocritical to say you’re going to defend the U.S. Constitution against Donald Trump, but you won’t use the power that you have right now to defend the U.S. Constitution and pass a welcoming city ordinance that truly defends the rights of all Chicagoans.”

Ramirez-Rosa and local immigration activists want to eliminate certain provisions in the current sanctuary policy that they said still allow local police to cooperate with federal immigration authorities.

Chicago Sues Department of Justice Over ‘Sanctuary ‘Status by Chicago Public Media on Scribd

Becky Vevea covers city politics for WBEZ. Follow her @beckyvevea.