President Donald Trump’s pick to replace Attorney General Jeff Sessions and oversee special counsel Robert Mueller’s Russia investigation has sharply criticized the probe in the past.

Matt Whitaker, a former federal prosecutor, was appointed as acting attorney general after Sessions handed in his resignation, the president announced Wednesday. Whitaker has served as Sessions’ chief of staff since September 2017.

To Trump’s unrelenting ire, Sessions was unable to rein in Mueller’s expansive probe into Russian interference in the 2016 presidential election and whether the president obstructed justice, given Sessions’ decision to recuse himself from the probe in March 2017.

With Sessions out of the picture, Trump has selected someone who has expressed significant skepticism about Mueller’s investigation, signaling the president could be pushing for an imminent end to it.

Whitaker, during an interview with CNN in July 2017, suggested that a potential future replacement for Sessions wouldn’t need to fire Mueller to kneecap the investigation.

“I could see a scenario where Jeff Sessions is replaced with a recess appointment and that attorney general does not fire Bob Mueller, but he just reduces his budget to so low that his investigation grinds to almost a halt,” Whitaker said at the time.

In August 2017, roughly a month before his appointment as Sessions’ chief of staff, Whitaker penned an op-ed for CNN in which he suggested the Russia investigation was “going too far” and could be “a witch hunt.”

“Mueller has come up to a red line in the Russia 2016 election-meddling investigation that he is dangerously close to crossing,” Whitaker wrote. “It is time for Rosenstein, who is the acting attorney general for the purposes of this investigation, to order Mueller to limit the scope of his investigation to the four corners of the order appointing him special counsel.”

He continued: “If he doesn’t, then Mueller’s investigation will eventually start to look like a political fishing expedition. This would not only be out of character for a respected figure like Mueller, but also could be damaging to the President of the United States and his family ― and by extension, to the country.”

Whitaker also has ties to a witness on Mueller’s grand jury, Sam Clovis. Clovis, whose 2014 Iowa state treasurer campaign Whitaker chaired, dismissed concerns that their connection could affect the investigation.

“It’s not relevant and Matt has high integrity,” Clovis told The Washington Post. “I’m very happy for him and he’ll do a fantastic job.”

Senate Minority Leader Chuck Schumer (D-N.Y.) on Wednesday called on Whitaker to recuse himself from the Mueller probe, citing his previous remarks on the matter.

“Given his previous comments advocating defunding and imposing limitations on the Mueller investigation, Mr. Whitaker should recuse himself from its oversight for the duration of his time as acting attorney general,” Schumer said in a statement.

Sen. Mark Warner (D-Va.), vice chairman of the Senate Intelligence Committee, echoed Schumer’s call.

“Given Mr. Whitaker’s public comments on the Special Counsel’s investigation and the President’s obvious self-interest in appointing him to the Acting AG role, Mr. Whitaker should recuse himself,” Warner tweeted.

Given Mr. Whitaker’s public comments on the Special Counsel’s investigation and the President’s obvious self-interest in appointing him to the Acting AG role, Mr. Whitaker should recuse himself. https://t.co/XuRpcT3Gxd — Mark Warner (@MarkWarner) November 7, 2018

Igor Bobic and Lydia O’Connor contributed reporting.