A former Fox News contributor who called the network a “propaganda machine for a destructive and ethically ruinous administration” in his resignation letter last week continued his scathing critique in a Washington Post op-ed Friday.

Retired Lt. Col. Ralph Peters reaffirmed in the op-ed that he decided to not renew his contract as Fox News’ strategic analyst due to “the network’s propagandizing for the Trump administration.”

“Today’s Fox prime-time lineup preaches paranoia, attacking processes and institutions vital to our republic and challenging the rule of law,” Peters wrote.

Peters expressed regret for his “error” in “waiting so long to walk away” because he thought he “could make a difference by remaining at Fox and speaking honestly.”

Peters said his troubles with Fox began around Fall 2016 when he was “blocked” from speaking on Russian affairs and the intelligence community — two subjects he said he “could offer real expertise” on.

“I did not hide my views at Fox and, as word spread that I would not unswervingly support President Trump and, worse, that I believed an investigation into Russian interference was essential to our national security,” Peters said.

Peters noted that he was “excluded from segments that touched on Vladimir Putin’s possible influence on an American president, his campaign or his administration.”

In the few months leading up to his resignation, Peters said he became a “disgruntled employee” who “hated walking into the Fox studio.”

Despite his criticism, Peters said that the network “never tried to put words in [his] mouth” nor was he explicitly told he was “taboo on Trump-Putin matters.”

Peters concluded his op-ed by stressing “there are many honorable and talented professionals at the Fox channels” despite how “Trump idolaters and the merrily hypocritical prime-time hosts are destroying the network.”

In an email to TPM Friday, Fox News spokesperson Caley Cronin denied Peters’ allegation that he was “blocked” from discussing certain subjects.

“There is no truth to the notion that Ralph Peters was ‘blocked’ from appearing on the network to talk about the major headlines, including discussing Russia, North Korea and even gun control recently,” Cronin said. “In fact, he appeared across both networks multiple times in just the past three weeks.”

Read Peters’ op-ed in The Post here.

This post has been updated.