Two months ahead of trial, federal prosecutors late Tuesday revealed new details of wiretapped conversations and other evidence they intend to use against four people accused in an alleged bribery scheme between Commonwealth Edison and then-House Speaker Michael Madigan.

Among the new revelations:

— A ComEd lawyer is expected to testify that the man accused of orchestrating the scheme, ex-lobbyist Michael McClain, had such a longstanding and close relationship with Madigan that he was sometimes referred to within ComEd as a “double agent.”

— Agents who searched McClain’s personal vehicle in 2019 discovered a handwritten ledger allegedly showing he was at Madigan’s beck and call “24/7,” helping to manage the Speaker’s ever-growing list of associates working as ComEd subcontractors as well as the “allotment of interns” Madigan was sending to the utility giant each summer.

— In 2016, McClain wrote a letter Madigan saying he wanted to let his “real” client know he was retiring from lobbying, but still willing to do “assignments” for him. “I am at the bridge with my musket standing with and for the Madigan family,” he wrote, according to a copy included in the filing.

— Former McPier boss Juan Ochoa is expected to testify how he enlisted the help of a member of Congress in 2017 to help repair his tattered political relationship with Madigan and ultimately secure a lucrative position on ComEd’s Board of Directors.

— Prosecutors also intend to call Ed Moody, the former Cook County Recorder of Deeds and longtime 13th Ward precinct captain, who will testify Madigan told him it was ok that he was being paid by ComEd for doing next to nothing because he was “a valuable political operative” and that campaign work “was what was important to Madigan.”

— And professor Dick Simpson, a former Chicago alderman, has been tapped as an expert witness who will describe for jurors “the structure, method, and operation of the Chicago political machine.”

The details were revealed in a 126-page filing known as a Santiago Proffer, which prosecutors are typically obliged to submit in advance of a conspiracy trial describing specific evidence, statements and actions between alleged co-conspirators they plan to present to the jury.

The trial, which is scheduled to begin with jury selection on March 6, promises to be the biggest political corruption trial at the Dirksen U.S. Courthouse since ex-Gov. Rod Blagojevich was convicted by a jury in 2011.

It will also offer a preview of many of the allegations against Madigan himself, who was indicted along with McClain last March on racketeering conspiracy charges alleging an array of corrupt schemes, including the alleged plan to use the power of his office to steer ComEd money to his cronies. That case has been set for trial in April 2024.

McClain, 75, of downstate Quincy, was indicted in November 2020 along with former ComEd CEO Ann Pramaggiore, ex-ComEd lobbyist John Hooker, and former City Club of Chicago head Jay Doherty. All of the defendants have pleaded not guilty.

Defense lawyers in the case did not immediately reply to the government filing.

Another defendant, former ComEd Vice President Fidel Marquez, has pleaded guilty and is expected to testify for the prosecution. Madigan’s former chief of staff, Timothy Mapes, meanwhile, is charged with lying to a federal grand jury about the case.

The ComEd conspiracy charges alleged McClain, a former legislator and lobbyist whose connections to Madigan go back to their time in the General Assembly together in the 1970s, orchestrated a scheme to funnel jobs and hundreds of thousands of dollars in payments from the utility to Madigan-approved consultants in exchange for Madigan’s assistance with legislation the utility giant wanted passed in Springfield.

The indictment also alleged ComEd agreed to hire numerous summer interns from Madigan’s 13th Ward, and install Ochoa on the company’s board of directors in order to curry favor with the then-powerful Speaker.

ComEd, meanwhile, entered into a deferred prosecution deal with prosecutors in July 2020, agreeing to pay a record $200 million fine and cooperate with the investigation in exchange for bribery charges being dropped in three years.

Madigan, who was dethroned from the speakership in January 2021, has pleaded not guilty to the criminal charges against him. He’s also vigorously defended making job recommendations, both before and after his indictment. Not only is “helping people find jobs not a crime,” Madigan wrote in 2020 to a legislative panel, it’s not even “ethically improper” for politicians to make job recommendations.

“To the contrary, I believe that it is part of my duties as a community and political leader to help good people find work — from potential executives to college interns, and more,” Madigan wrote. “What an employer chooses to do with that recommendation rests solely with their discretion.”

Many of the details in the document filed on Tuesday have already been revealed in other court filings. But the government proffer lays out in the highest relief so far what some of the key witnesses are expected to tell the jury, including Marquez, who secretly recorded conversations for investigators.

According to the filing, Marquez will testify that after Pramaggiore became CEO of ComEd, she sought to build up a relationship with Madigan that she thought was poor and detrimental to the company’s goals.

Working closely with McClain, who often referred to the Speaker as “our friend” but almost never by name, Pramaggiore arranged for payments to be made to Madigan-approved associates through Doherty’s consulting company, Jay D. Doherty & Associates, and several other lobbying firms that served as “intermediaries,” the government filing alleged.

“Marquez is expected to further testify that while paying individuals as requested by Madigan and McClain did not guarantee legislative success, the purpose of the payments was to influence Madigan and to ensure Madigan did not act against ComEd and its legislative requests and agenda due to a failure to fulfill his hiring requests,” the filing stated.

jmeisner@chicagotribune.com