More than 1,100 former Justice Department employees have signed an online petition.
Politico reports the letter urges Attorney General Bill Barr to resign.
It also commends the four prosecutors who withdrew from the Roger Stone case.
Last week, all four prosecutors quit the Stone case after what they perceived as interference from the White House.
The prosecutors had recommended a seven- to nine-year prison sentence after Stone was convicted of lying to Congress and of obstruction.