WASHINGTON (NewsNation) — Defense Secretary Lloyd Austin reminded America on Monday that 300 military nominations are being held up in the U.S. Senate, including top uniformed leaders and the next Chief of Naval Operations.

Austin said that because of an effort by Alabama Sen. Tommy Tuberville, three military services are operating without Senate-confirmed leaders for the first time in the history of the Department of Defense.

“This is unprecedented. It is unnecessary, and it is unsafe,” Austin said. “And this sweeping hole is undermining America’s military readiness. It’s hindering our ability to retain our very best officers. And it is upending the lives of far too many American military families.”

Tuberville followed through with a promise to delay civilian and flag officer nominations in the Pentagon, protesting the DOD policy that provides leave and reimbursement for service members who need to travel to get an abortion. By doing this, he is currently holding 300 military nominations.

Tuberville, a member of the Senate Armed Services Committee, has said he will continue to stymie the nominations until the Defense Department rescinds the abortion policy.

Even fellow Senate Republicans were unable to strike a deal with the Alabama senator to break the hold prior to the August recess, which has virtually ensured that the hold will stretch until early September at least.

“Our troops deserve better. Our military families deserve better. And our allies and partners deserve better and our national security deserves better,” Austin said.

Austin had previously said not approving the recommendations for promotions actually creates a ripple effect in the force that makes the U.S. less ready when the country needs to be.

The GOP senator’s hold forces the Democrat-controlled Senate to consider and vote on each nomination rather than approving them in batches, dragging out the process.

The approval of military nominations and promotions requires unanimous participation of Senate members, and Tuberville says he has no plans of backing down.

For now, the fight is at a stalemate. Democrats say a vote on every nominee could tie up the Senate floor for months, and they don’t want to give in to Tuberville’s demands and encourage similar blockades of nominees in the future.

The Hill and The Associated Press contributed to this report.