CHICAGO (CBS) — Federal prosecutors are asking a judge for more time to indict Ald. Edward Burke (14th), nearly two weeks after he was charged with trying to put the squeeze on to businessmen seeking to renovate a Burger King on the Southwest Side.

Prosecutors typically have 30 days after an arrest to return an indictment, but in a four-page motion filed Monday, the feds sought a 90-day extension, which would give them until May 3, or more than two months after the upcoming election, to indict Burke.

“The government is conducting a diligent and thorough investigation into this case, but certain factors have led to this request for an extension. These factors include the complex nature of this public corruption case, and the fact that the investigation is ongoing. Thus, due to the complex nature of this investigation, the government cannot appropriately conclude the investigation within the time allowed,” prosecutors wrote.

Also on Monday, Burke waived his right to a preliminary hearing in the case, which had been scheduled for Friday. Such a hearing would determine if there is probable cause for the charge filed against him, but such hearings are routinely superseded when prosecutors return a grand jury indictment.

If U.S. Magistrate Judge Sheila Finnegan grants prosecutors’ request for an extension, they would have until May 3 to return an indictment against Burke.

Burke, 75, has been charged with one count of attempted extortion for allegedly using his position as alderman to illegally pressure two executives with a fast food restaurant company to hire his law firm for property tax work.

The criminal complaint against Burke also accuses the alderman of asking one of the executives to make a campaign contribution to another politician in exchange for his support for a restaurant renovation project.

That unnamed politician was later revealed to be Cook County Board President Toni Preckwinkle, who is running for mayor and has said she didn’t personally know about the donation or alleged extortion. Her campaign has said the entire donation was returned, and she has not been accused of a crime.

Burke resigned as chairman of the City Council Finance Committee after he was charged but has said he will continue to seek reelection on Feb. 26, when he faces three opponents, including Tanya Patino, who has the backing of Congressman Jesus “Chuy” Garcia.

The congressman also endorsed newly elected Illinois State Rep. Aaron Ortiz, who defeated Burke’s brother, Dan, in last year’s Democratic primary. Ortiz is also Patino’s boyfriend.

While Burke so far faces only one criminal charge, the complaint against him revealed prosecutors had already tapped his cell phone before the alleged extortion attempt began in May 2017, suggesting they were already investigating something else involving Burke.