Rep. Jason Chaffetz. Alex Wong/Getty Images The Republican and Democratic heads of the House Committee On Oversight and Government Reform filed a letter on Thursday requesting the independent government watchdog begin a review of President Donald Trump's counselor following her endorsement of Ivanka Trump's fashion line.

In a letter to the Office of Government Ethics, Reps. Jason Chaffetz and Elijah Cummings wrote that they had "extremely serious concerns" that Kellyanne Conway violated federal ethics rules when she appeared on Fox News on Thursday and explicitly endorsed Ivanka Trump's fashion line, which was dropped by Nordstrom after the retailer claimed the sales were slow.

"Conway's statements from the White House using her official title could appear to constitute an explicit endorsement, and advertisement for Ivanka Trump's personal business activities," the ranking members wrote.

The letter continued: "We request you review Conway's statements and act promptly based on the basis of your findings. We also ask you to report back to the committee with your recommendations for disciplinary action, if warranted."

In a corresponding tweet, Chaffetz condemned Conway's endorsement:

The letter permitted the OGE to review Conway's conduct for a potential ethics violation and recommend a punishment, including "reprimand, suspension, demotion, or dismissal."

The letter also acknowledged that there was a likely conflict of interest, as the president would enforce any recommended disciplinary action. Trump himself slammed Nordstrom on Wednesday for dropping his daughter's line.

Appearing on "Fox & Friends" on Thursday, Conway dismissed Nordstrom's decision to drop Ivanka Trump's line.

"Go buy Ivanka's stuff, is what I would say. I hate shopping — I'm going to buy stuff today," Conway said.

"It's a wonderful line. I own some of it," Conway added. "I'm going to give a free commercial here. Go buy it today, everybody. You can find it online."

Hours before the OGE letter, Cummings released his own request seeking disciplinary action against Conway.

"This appears to be a textbook violation of government ethics laws and regulations enacted to prevent the abuse of an employee’s government position," Cummings wrote on Thursday. "Since the Committee has direct jurisdiction over the ethics laws applicable to White House employees, I request that the Committee make an official referral of this matter to the Office of Government Ethics and request that it report back to the Committee as soon as possible with its findings."