The lawsuit is being drafted by the city's Law Department and will be filed in the Circuit Court of Cook County, spokesman Bill McCaffrey said.
Thursday was the city's deadline day for the "Empire" actor to reimburse the city more than $130,000 for the cost of the investigation into the alleged racist and homophobic attack that police determined was a hoax.
Last week, Cook Countyagainst Smollett, after he agreed to forfeit his $10,000 bail, and performed 16 hours of community service.
Smollett has maintained his innocence, and said he was "truthful and consistent" from the start, but prosecutors have said they do not believe he is innocent, and Mayor Rahm Emanuel has said the actor owes Chicago an apology.
Last Thursday, the mayor had the city's Law Department send Smollett a letter titled "Re: Repayment of Investigation Costs for False Police Report," requiring "immediate payment of the $130,106.15 expended on overtime hours in the investigation of this matter."
The March 28 letter said, if Smollett does not pay within seven days, the city could prosecute him for making a false statement and take him to civil court to seek up to three times that amount as damages, plus court costs and attorney's fees.
With a civil case, the standards for provingwould be lower than in criminal court. While a criminal trial requires proof beyond a reasonable doubt for a conviction, a civil trial would require the city to prove only that a "preponderance of evidence" — meaning it's more likely true than not — that the incident was a hoax orchestrated by Smollett.
Smollett said he was attacked by two men, who doused him with a chemical and put a noose around his neck in January.
The case added pressure on beleaguered State's Attorney Kim Foxx as Chicago's police union and a host of suburban police chiefs have been calling on her to resign, CBS Chicago adds.
The Chicago Fraternal Order of Police (FOP) said it's not just Foxx dropping the charges against Jussie Smollett that's behind their call for resignation. Their disaffection began with lack of charges in attacks on police officers.
"We see people with a dislocated knee. We see people who have been bitten, almost had fingers bitten off. And we can't get felony charges on that. That's a problem," said FOP president Kevin Graham.
The overall feeling among these cops: Foxx is going light on charges.
"We want to see criminals prosecuted and we want to see people convicted," Graham said.
Particularly, the police cite three Foxx policies: Not prosecuting theft felonies under $1,000 in value, or most drivers with invalid licenses or most small marijuana cases.
"What she's doing is enabling the offenders," said Steven Stelter of the West Suburban Chiefs Association. "The bad guys are not being held accountable."
But Foxx defenders, like attorney Brendan Shiller allege her attackers are motivated primarily by race.
"She, for the first time in the history of this county, has exercised prosecutorial discretion in away that does not put black and brown men in prison every single day, and that's something the FOPs can't stand," said attorney Brendan Shiller.
And notably, not a single African American police chief stood among the many from suburban towns urging Foxx to go.
"I don't know why other chiefs aren't here. I can't answer that," Graham said.
Harvey Police Chief Gregory Thomas who is African American and was not at the news conference, said it was premature to ask Foxx to resign. She said she welcomes a federal review of the Smollett case.
It's something the FOP is also demanding. Foxx indicated she has no intention of stepping down.