This was confirmed by members of the Committee in a letter to the head of the Ministry of Justice.

23 Democrats on the House Judiciary Committee sent a letter confirming that justice Department Chief William Barr will testify to the Committee on March 31. Questions to Barr are related, as noted, to his role as head of the Department of justice and the possible “influence” of President Trump on the work of the Department.

“Since President Trump took office,” the letter addressed to Barr said,” we have repeatedly warned You and your predecessors that the misuse of our criminal justice system for political purposes is dangerous to our democracy and unacceptable to the Judiciary Committee of the House of representatives. Our Republican colleagues warned the Justice Department about the same thing. In this regard, our position has remained constant and bipartisan for several years.”

“During Your tenure as US Attorney General,” the document goes on to say, “You became involved in conduct in matters related to President [Trump] that caused significant concern to the Legal Committee. In the past week alone, you have taken steps that cast extremely serious doubt on the quality of your leadership of the Ministry of justice. These include, in particular:
-developments related to the removal from office of Prosecutor Jessie Liu, who oversaw the trial of Donald Trump’s Deputy Chief of staff-Rick Gates, former national security adviser to President Trump Michael Flynn and longtime political adviser to President Trump Roger Stone;

-developing a new “process” by which President Trump’s lawyer, Rudy Giuliani, can, through You, distribute information from the Justice Department about the President’s political rivals;
-the decision to ignore the work of Your prosecutors and significantly reduce – apparently at the request of the President – the severity of the sentence recommended for Roger Stone, who was found guilty of perjury under oath. This decision led to the fact that all four prosecutors involved in the case refused to participate further in the process in protest.

These comments are not the only ones that our Committee intends to discuss with You when you appear to testify, but they are enough to focus all our attention on them at this stage,” the message reads.

Earlier, the head of the White House expressed outrage at the recommendation of prosecutors, who called for Roger stone to be sentenced to prison for a term of 7 to 9 years for violations related to the 2016 election.

“This is a terrible and very dishonest situation,” President Trump tweeted. – The real crimes were committed on the other side, and nothing is done about them. We must not allow perversion of justice!”

After that, on Tuesday, the Ministry of justice unexpectedly withdrew this recommendation, calling it “unnecessary and unfounded.” At the same time, all four prosecutors who participated in the process, indeed, as stated in the letter of the democratic congressmen, resigned.