Nineteen Republican congressmen signed on to a letter sent out Friday requesting congressional hearings to keep special counsel Robert Mueller and his team of lawyers accountable.

“This team has sweeping authority and an open-ended mission, yet they are allowed to operate largely in secret, selected by and ultimately accountable to only one person: Mr. Mueller himself,” the letter sent to House Judiciary Committee chairman Bob Goodlatte and Senate Judiciary Committee chairman Chuck Grassley states.

Texas Republican Rep. Brian Babin started asking his colleagues to sign the letter in August. The congressmen who signed on include: Iowa Rep. Steve King, Arizona Rep. Trent Franks, California Rep. Duncan Hunter and Virginia Rep. Dave Brat.

“With numerous reports emerging almost every day on possible conflicts of interest and allegations of political bias, it would be in the interest of both the public and the Special Counsel team to speak to the American people through their elected representatives in Congress,” the letter continues on to say. “Accordingly, we respectfully request that one of broth of the Judiciary Committees immediately convene a public and open hearing or series of hearings to bring Mr. Mueller and his team out of the shadows and into the public square.”

Mueller’s investigation has broad authority. He is authorized to investigate any coordination or links between the Russian government and the Trump campaign; charges such as perjury, obstruction of justice, intimidation of witnesses and destruction of evidence and any matters that “arose or may arise directly from the investigation.”

The former FBI director, a registered Republican, has hired 17 attorneys, nine of which have given around $65,000 in political donations to Democratic candidates.

President Trump has previously criticized these hires.

“I can say that the people that have been hired are all Hillary Clinton supporters,” Trump told Fox News. “Some of them worked for Hillary Clinton. I mean the whole thing is ridiculous, if you want to know the truth, from that standpoint.”

Letter to Grassley-goodlatte Re Special Counsel Accountability by Alex Pfeiffer on Scribd