President Donald Trump’s former chief of staff John Kelly reportedly considers the U.S. president among the most contemptible people he has known. According to an excerpt from a CNN special set to air Sunday night, Kelly told friends, “The depths of his dishonesty is just astounding to me. The dishonesty, the transactional nature of every relationship, though it's more pathetic than anything else. He is the most flawed person I have ever met in my life.”

In addition to Kelly, the program, The Insiders: A Warning from Former Trump Officials, includes interviews with former national security adviser John Bolton, former Health and Human Services immunologist Rick Bright, and John Mitnick, former general counsel at the Department of Homeland Security, which Kelly oversaw for just eight months before his ill-fated 17-month stint as White House chief of staff.

Trump has been quick to lash out at old hires that dare speak out against him. When Kelly publicly defended Army Lt. Col. and whistleblower Alexander Vindman earlier this year, Trump took to Twitter to express his displeasure with the retired Marine Corps general. “When I terminated John Kelly, which I couldn’t do fast enough, he knew full well that he was way over his head,” Trump complained.