As Attorney General William Barr testified to the Senate Judiciary Committee Wednesday about Special Counsel Robert Mueller's report on interference in theb 2016 presidential election, the Washington Post published Mueller's full letter to Barr in which he expressed concerns about Barr's response to the report.

CNN and the New York Times published reports of the the existence of the letter late Tuesday.

In his letter, Mueller says he has concerns about Barr's March 24 letter to Congress, saying the letter has led to "public confusion about critical aspects of the results of our investigation."

"This threatens to undermine a central purpose for which the Department appointed the Special Counsel: to assure full public confidence in the outcome of the investigations," the letter reads.

Read the full letter in the window below.