WASHINGTON (Reuters) - U.S. acting Attorney General Matthew Whitaker, whose unorthodox appointment by President Donald Trump has raised concerns among Democrats about the future of the U.S.-Russia probe, will testify before the House Judiciary Committee on Feb. 8, the panel said on Tuesday.

U.S. Acting Attorney General Matthew Whitaker listens as U.S. President Donald Trump holds a meeting about border security with state, local and community leaders in the Cabinet Room at the White House in Washington, U.S., January 11, 2019. REUTERS/Leah Millis/File Photo

In one of the first oversight appearances by a Trump administration official in the new Democratic-controlled House of Representatives, Whitaker is due to testify on a range of topics including U.S. Special Counsel Robert Mueller’s investigation of alleged Russian meddling in the 2016 presidential election.

A Justice Department spokesman confirmed the arrangement but declined further comment.

A Trump loyalist, Whitaker was appointed by Trump without Senate confirmation after the president ousted Attorney General Jeff Sessions in November. Democrats said the appointment violated the U.S. Constitution and they viewed the move as a possible ploy by the White House to undermine Mueller’s efforts to determine whether Trump campaign members colluded with Russia.

Trump denies any collusion and has condemned the Mueller investigation as a “witch hunt.” Russia also denies any interference in the U.S. election.

It is not clear how much longer Whitaker will head the Justice Department. William Barr, who served as attorney general under former President George H.W. Bush, has been nominated for the job by Trump. Senate confirmation hearings for Barr began this week.

“If you plan to invoke executive privilege in an attempt to avoid answering any particular question, I ask that you consult with the White House well in advance of the hearing,” House Judiciary Committee Chairman Jerrold Nadler said in a letter on Tuesday to Whitaker released by the panel.

The Democratic-led committee did not issue a subpoena to compel Whitaker’s testimony, according to aides. But Nadler threatened to do so earlier this month if it became necessary.

Whitaker had agreed to testify before the committee in January. But Nadler said last week the Department of Justice was citing the partial government shutdown as a reason to delay Whitaker’s appearance until Feb. 12 or 13.

The Whitaker hearing is set to begin on Feb. 8 at 9:30 a.m. (1430 GMT), regardless of whether the government shutdown continues, an aide said.