Democrats on the House Judiciary Committee are launching an investigation into potential political intervention in the case of Roger Stone, requesting interviews with 15 individuals currently or formerly employed with the Justice Department.

"The Judiciary Committee needs to examine a range of recent actions that smack of political interference, including the Department's withdrawal of the Roger Stone sentencing recommendation," Chairman Jerry Nadler wrote in a letter to Attorney General William Barr, saying the committee found this and several other matters "deeply troubling." Barr is appearing before the committee on March 31.

"There is also a long history of Attorneys General cooperating in oversight inquiries led by both Democrats as well as Republicans, and given the stakes for our nation, we expect Attorney General Barr's full cooperation here," Nadler continued.

Get Breaking News Delivered to Your Inbox

Stone was convicted of lying to Congress, among other charges, and federal prosecutors initially recommended a seven-to-nine-year prison sentence. After President Trump complained on Twitter that the recommendation was "horrible and very unfair," the Justice Department overruled the prosecutors and asked for a lighter sentence. All four of the prosecutors on Stone's case withdrew in protest. Stone was sentenced to a little over three years in prison. Mr. Trump has repeatedly criticized the judge in Stone's case and one of the jurors on Twitter.

Barr recently said in an interview that Mr. Trump's tweets about the Justice Department "make it impossible to do my job." He also said that he was not influenced by the president in the decision to overrule the prosecutors in the sentencing guidelines for Stone.

The four prosecutors who withdrew from the case are among the witnesses Nadler requested in his letter to Barr.

In a statement, the committee's top Republican, Congressman Doug Collins, slammed Nadler for not doing more to investigate abuses of warrants conducted under the Foreign Intelligence Surveillance Act (FISA).

"The fact that Democrats sent these requests just two days after cancelling our FISA markup and putting our national security at risk is further proof that they care about one thing and one thing only: Attempting to take down President Trump," Collins said.