WASHINGTON — Rep. Adam Schiff, D-Calif., warned acting Attorney General Matthew Whitaker that he should recuse himself from oversight over special counsel Robert Mueller's Russia probe amid concerns about his view of the investigation.

"If he doesn't recuse himself, if he has any involvement whatsoever in this Russia probe, we are going to find out whether he made commitments to the president about the probe, whether he is serving as a back channel to the president or his lawyers about the probe, whether he's doing anything to interfere with the probe," Schiff said Sunday on NBC's "Meet the Press."

"Mr. Whitaker needs to understand that he will be called to answer, and any role that he plays will be exposed to the public. We don't want there to be any ambiguity about that."

Whitaker's sudden ascension to the helm of the Justice Department has prompted criticism from Democrats who believe he could undermine the special counsel's investigation, as well as from legal experts who question whether Whitaker is constitutionally eligible to serve in the position.

Whitaker, who served as former Attorney General Jeff Sessions's chief of staff until Sessions was ousted by President Donald Trump last Wednesday, is not expected to recuse himself from Mueller's investigation. That has raised concerns because of the new acting attorney general's past statements on the probe.

While he was a CNN contributor in 2017, Whitaker mused about a new attorney general frustrating Mueller's investigation by reducing "his budget to so low that his investigation grinds almost to a halt."

And he's offered conflicting statements as to whether he believes there was Russian interference in the 2016 election.

During a 2017 appearance on the Wilkow Majority Show on satellite radio, he said "there was interference by the Russians into the election, but that was not collusion with the campaign.”

But during an appearance on the Chosen Generation Radio Show earlier that year, he accused the "left" of "trying to sow this theory that essentially Russians interfered with the U.S. election, which has been proven false."

"They did not have any impact in the election, and that has been very clear from the Obama administration," Whitaker said.

"They are trying to suggest that essentially the Trump campaign had these deep ties into Russia which is not true and I guess what they, that they are trying to conflate that somehow Russia and the Trump campaign sort of conspired to influence the election. It is crazy but at the same it has been dominating the news coverage."

During his Sunday interview, Schiff said some of those comments raised concerns.

Top House and Senate Democrats, including Schiff as the top Democrat on the House Intelligence Committee, released a letter Sunday morning asking the Justice Department's top ethics official to disclose whether he believes Whitaker should recuse himself from overseeing the investigation.

"This is someone who's made repeated and prejudicial comments against the investigation, someone who has made false statements about it, claiming that the Russians really had no impact on our election," Schiff said Sunday.

Whitaker's relationship with the Russia probe is just one part of an ever-growing list of potential Trump administration subjects Democrats are seeking to investigate. While Schiff admitted investigations are "sexy," he said Democrats have to make sure their top priority in Congress is an agenda that goes beyond congressional probes of Trump.

Elissa Slotkin, the Democratic congresswoman-elect from Michigan's 8th Congressional District, agreed that Democrats have to "watch it" to be sure an anti-Trump agenda doesn't overtake their message.

"If we can't, as Democrats, as elected officials, provide for people and help their pocketbook or their kids, we do not deserve their vote," she said Sunday on "Meet the Press."

"We can walk and chew gum," she said. "We can protect American values and hold accountability for the executive branch. But if we can't do things on health care and infrastructure, we're going to lose people."