Update, Nov. 30, 2022: This story has been updated to include a statement from a Joe Mansueto spokesperson, who reached out after the story was published.

For months, Chicago Mayor Lori Lightfoot has pushed a controversial plan to turn over public housing land to a professional soccer team owned by an influential billionaire.

In mid-November, that billionaire owner of the Chicago Fire Football Club, Joe Mansueto, donated $25,000 to the mayor’s reelection campaign.

And now, a member of the City Council is asking the city government’s top watchdog and ethics officials to investigate whether the contribution violates prohibitions on pay-to-play politics.

“I believe this represents a gross & familiar abuse of power and, at a minimum, a potential violation of the City of Chicago’s Governmental Ethics Ordinance,” Alderman Raymond Lopez wrote in a letter to Deborah Witzburg, the city’s inspector general, and Steve Berlin, executive director of the city’s Board of Ethics. Lopez cited sections of the ordinance that prohibit gifts and political contributions meant to influence official decisions.

Mansueto, though an ally, had never given to Lightfoot’s political fund before his Nov. 17 contribution, according to election disclosure records. (Mansueto’s family foundation has donated to a number of cultural and nonprofit entities, including ProPublica.)

On Wednesday, Lightfoot’s campaign spokesperson praised Mansueto and fended off the criticism.

“Mr. Mansueto has been a socially responsible leader in Chicago’s business community, investing in our neighborhoods and supporting a range of philanthropic initiatives. We are proud to have his support for our grassroots campaign,” spokesperson Christina Freundlich wrote in a statement.

She added: “Government decision-making is firewalled from political campaign activities, and our team executes a rigorous vetting process on every contribution to ensure we have complied with all campaign finance rules and laws.”

A spokesperson for Mansueto did not address the campaign contribution but stressed that the business leader is committed to the city. “Joe believes in investing in historically disinvested parts of Chicago, a vision he shares with Mayor Lightfoot as a way to lift up the city as a whole,” the spokesperson wrote in a statement

Mansueto made the donation the same week Lightfoot released the first ads in her bid for reelection against 10 challengers in February. And it came as officials work to finalize a deal that would let Mansueto’s team take over 23 acres of valuable land that have long been set aside to house low-income families.

At Lightfoot’s behest, the Chicago Housing Authority agreed to lease the site to the Fire so the team can build a new training facility. But the Lightfoot administration and the CHA have kept many of the key details secret. The CHA did not conduct a formal bidding process, and it has refused to release a copy of the proposed agreement or show how it determined the value of the land.

Lopez is one of Lightfoot’s leading council critics, but in September he sided with her and voted in favor of a zoning change the Fire needed to build the new practice facility. He said in an interview that he still supports the Fire’s project but wrote the letter with “disdain” for the mayor’s decision to accept the campaign donation.

“I look forward to the independent investigation by the IG,” he said.

On Wednesday, as Lopez sent his letter, CHA residents and housing advocates protested the land deal outside the headquarters of Morningstar, the investment research firm that Mansueto founded and serves as executive director.