The Justice Department’s sentencing instructions for Roger Stone “were based on political considerations,” according to a member of special counsel Robert Mueller’s team who led the successful prosecution of the longtime Trump associate.

Aaron Zelinsky, who was a special assistant U.S. attorney in Washington, withdrew from the case in February along with three other prosecutors following the Justice Department’s decision to walk back its sentencing recommendation of seven to nine years in prison. Zelinsky, who now works for the U.S. attorney’s office in Maryland, will testify before the Democratic-led House Judiciary Committee on Wednesday.