Chicago Mayor Lori Lightfoot on Monday told the CEO of Commonwealth Edison she’s “deeply disturbed” by the utility giant’s role in an ongoing federal bribery scandal, and that company’s response so far has been “inadequate.”

In a letter, sent to ComEd CEO Joseph Dominguez and obtained by WBEZ, Lightfoot said in order to enter into another franchise agreement with ComEd, the company needs to implement a comprehensive ethics reform plan.

“ComEd’s breach of public trust is far from over as far as the City of Chicago is concerned,” Lightfoot wrote. “We expect a significant commitment from the company to right historic wrongs through its own internal ethics reforms[.]”

She also asks ComEd to align with her administration’s priorities “around energy and sustainability, equitable economic development, utility affordability and transparency.”

Earlier this month, ComEd agreed to a $200-million dollar fine as part of a deferred prosecution agreement with federal prosecutors.

“I can only imagine the significant impact a $200 million dollar investment of money in the city (versus a fine) would have on improving our neighborhoods, assisting low-income customers, or achieving clean energy goals,” Lightfoot wrote.

Lightfoot, herself a former federal prosecutor, told Dominguez in the letter that the proposed monitoring under that agreement “is not sufficient to rebuild trust and account for this egregious behavior.”

“We have a lot of work to do to rebuild trust, and our commitment to working collaboratively with the City is stronger than ever,” said Paul Elsberg, ComEd’s VP of Communications.

In a statement, Elsberg said the company has fully cooperated with the U.S. Attorney’s Office from the start of the investigation. He also noted that ComEd has implemented four new mandatory policies governing how employees interact with public officials and appointed an ethics and compliance team led by a former SEC official.

By entering into the deferred prosecution agreement, ComEd admitted to bribing state government officials in order to curry favor with powerful Illinois House Speaker Michael Madigan and win favorable government actions in Springfield. The prosecution of that crime would be called off if ComEd follows certain guidelines over the next three years.

The investigation into Madigan is still ongoing. The House Speaker and Democratic Party of Illinois boss has said he’s done nothing wrong.

The letter comes just days before ComEd executives are scheduled to appear before the City Council Committee on Environmental Protection and Energy. It also comes as activists are renewing a push to cut ties with ComEd and have the city run it’s own electric utility.

Lightfoot has said that it would be too costly and complex for the city to take over the business of distributing electricity to residents. Her administration hired a consultant to study the feasibility of doing that.

On Monday, Ald. Daniel La Spata called on the mayor to release that study, which he said is finished.