Retired Lt. Gen. Mark Hertling said Sen. Tommy Tuberville, R-Ala., is "despicable" and is "damaging the national security of our nation" by blocking senior military promotions.
Tuberville first imposed blocks on President Joe Biden's nominees in protest of the Department of Defense's new policy to pay travel costs for service members seeking abortion or reproductive care.
Tuberville has vowed to maintain the hold until Defense Secretary Lloyd Austin changes course or Tuberville gets a vote on the issue.
Hertling's comments came in a Monday night tweet. He wrote: "This despicable man @SenTuberville is knowingly continuing to further misplaced distrust of our institutions & he is significantly damaging the national security of our nation.
"@GOPSenators: you all need to stop this. He is an embarrassment to all of you as he continues."
Newsweek reported that as a result of Tuberville's blocking, the Marine Corps is without a confirmed leader for the first time in 164 years. Former Commandant Gen. David Berger retired on Monday.
Hertling, former commander of the U.S. Army in Europe, also retweeted a video of Tuberville being interviewed by CNN in which Tuberville said it was an "opinion" that white nationalists are racist.
CNN anchor Kaitlan Collins said the definition of a white nationalist is someone who believes that the white race is superior to other races. Tuberville said: "Well, that's some people's opinion."
Asked for his opinion, Tuberville said: "My opinion of a white nationalist, if someone wants to call them white nationalist, to me is an American."
Tuberville added: "If people think a white nationalist is a racist, I agree with that."
Last month, White House press secretary Karine Jean-Pierre took aim at blocks on military promotions by Tuberville, saying they were a "threat to our national security."
"What the senator is doing by holding these nominations, it's a threat to our national security, period," Jean-Pierre said. "These are important nominations that we need, that the American people need to keep our country safe."
Tuberville's office did not immediately respond to a request for comment.