The Chicago Board of Elections is expected to field an objection to Rahm Emanuel's candidacy sometime after the opening of business next Tuesday.
Lawyers will allege that Emanuel has not lived in Chicago for the required one year prior to running for mayor.
Emanuel indicated Friday that he will cite other sections of election law in his fight to remain on the ballot.
After he accepted the endorsement of union plumbers Friday afternoon, Emanuel listed his pedigree as a true Chicagoan.
"I was born in the city of Chicago," said Emanuel. "I was a congressman from the City of Chicago. I raised my kids in the City of Chicago. I own a home here in the City of Chicago."
However, because Emanuel has not lived for the past year in the home that he leased to a tenant during his service as White House chief of staff, his residency is likely to be challenged at the board of elections next week. The tenant is still in Emanuel's Chicago home.
While none of five other candidates for mayor will be plaintiffs in the case, ABC7 has learned that supporters of one or more of them will pay the expenses of an election lawyer.
"I don't think a few individuals should deny the people of Chicago a chance to have that choice," said Emanuel.
A section of Illinois election law says: "No elector or spouse shall be deemed to have lost his or her residence in any precinct or election district in this state by reason of his or her absence on business of the United States, or of this state."
City Clerk Miguel del Valle, another candidate for mayor, says he won't spend any of his money or time trying to keep Emanuel off the ballot.
"I want to talk about how it is that we improve our neighborhoods - how it is that we ensure balanced growth, balanced development in the City of Chicago?" said del Valle.
A spokesman for another candidate, State Senator James Meeks, questioned how Emanuel, living in Washington, was allowed to vote in Chicago after Emanuel's name was purged from city voter rolls.
The statement from the Meeks campaign asked that Emanuel "assure the people of Chicago that no political or personal favors play a role in how he conducts his business."
Emanuel was asked if the looming legal battle would be distraction.
"I don't think it's a distraction from the people that are standing here," said Emanuel. "They came here to talk about their jobs and about how to grow."
The board of elections will make the initial decision regarding Emanuel's qualifications to run for mayor.
That decision could be appealed to the circuit courts and up as far as the state supreme court.
At this time, no one expects the matter to be resolved until sometime in January, when the campaign is in full swing.
So far, nine candidates have filed petitions to be on the ballot in the race for mayor.
They are Gery Chico, Danny Davis, Wilfredo De Jesus, Miguel del Valle, Rahm Emanuel, M. Tricia Lee, Carol Moseley Braun, Tyrone Carter and Jay Stone.
More candidates are expected to join the field. Monday is deadline for filing petitions.