House Oversight Committee Chairman Rep. Jason Chaffetz (R-Utah) said he will refer White House senior adviser Kellyanne Conway for an ethics investigation, after she promoted Ivanka Trump’s fashion line during a Thursday appearance on Fox News.

Chaffetz told reporters on Capitol Hill that Conway’s remarks were “clearly over the line” and “unacceptable,” and that he and the top Democrat on the committee, Rep. Elijah Cummings (D-Md.), would jointly refer Conway to the Office of Government Ethics for an investigation.

“It should have never happened, and they better learn this lesson very quick,” Chaffetz told NBC.

Chaffetz was referring to Conway’s appearance on “Fox and Friends” Thursday morning, when she defended President Donald Trump’s attack against Nordstrom for dropping his daughter’s fashion line by advertising the brand.

“It is just a wonderful line. I own some of it,” Conway said. “I’m going to give a free commercial here. Go buy it today, everybody. You can find it online.”

Conway appeared to violate a federal regulation stating that government employees cannot use their public office to endorse products, quickly raising complaints from ethics watchdog groups.