Months into his hold on military nominees, Sen. Tommy Tuberville of Alabama is still not relenting despite efforts by some of his own Republican colleagues to try and give him alternatives to back off his blockade.

Since Tuberville announced his effort in March, there is now a backlog of 250 military appointments, a number only expected to grow in the months ahead. Pentagon officials have warned it's having an impact on national security and military readiness, Senate GOP Leader Mitch McConnell has publicly said he doesn't back it and one Senate Democrat is warning it could become a campaign issue for the GOP.

"I'll use it in my campaign. It's gonna kill them," Democratic Sen. Jon Tester of Montana warned, saying he hadn't yet but was weighing it. "It's gonna hurt (Republicans) bad."

But the Alabama senator pledges he won't back down until he has a vote on the Senate floor on codifying the Biden-era Pentagon policy that ensures service members can access abortion services. Tuberville maintains he's never heard from the White House nor from Democratic Senate Leader Chuck Schumer to negotiate an end to his hold. Instead, he argued he's only had a brief conversation with Defense Secretary Lloyd Austin and heard from colleagues who have attacked him for his tactic.

"The White House has not reached out to me once in four months," Tuberville said from the Senate floor Thursday.

Responding to criticism from his colleagues, Tuberville said "frankly, this kind of behavior just steels my resolve."

Behind the scenes, some of Tuberville's colleagues have tried to talk with Tuberville about alternatives. Multiple GOP senators including Armed Services Committee top Republican Roger Wicker, Texas Sen. John Cornyn and Sen. Joni Ernst of Iowa have talked with Tuberville, careful not to deploy a pressure campaign, but instead understand what he's aiming to accomplish. Tuberville told CNN that Ernst talked with him specifically about her bill, which seeks to rescind the DOD policy. She's been promised a vote on her legislation in committee next week ahead of a mark-up of the National Defense Authorization Act.

"Joni Ernst and I talked a little bit about her bill, but I am not going to take anything that's gonna go through committee if it's not gonna go through the floor," Tuberville said.

It's possible that Ernst's bill could pass in committee. Sen. Joe Manchin, a moderate Democrat from West Virginia, serves on the Armed Services Committee and has a track record of crossing party lines on abortion issues. But, there still isn't a guarantee it would get a vote on the Senate floor. Ernst told CNN Thursday she had not discussed it with Schumer. It's also not the vote that Tuberville wants.

Tuberville says the only way he will end his hold on military promotions is if there is a vote on the Senate floor to codify the Pentagon policy that subsidizes travel for service members seeking abortions outside of their state. Then, if that vote fails, Tuberville wants the Pentagon to take the policy off the books. A proposal to codify Pentagon policy wouldn't have the 60 votes needed to pass in the US Senate.

Democrats have been resistant to give into Tuberville's unprecedented move.

"I am not going to do anything to help reward Senator Tuberville as he tries to turn our military into one more political football," said Sen. Elizabeth Warren, a Democrat from Massachusetts who chairs the subcommittee responsible for Pentagon personnel. "Right now Senator Tuberville is undermining national security."

Tuberville's hold cannot ultimately stop Pentagon nominees from being approved, but moving through dozens of military promotions, which typically are so uncontroversial that they can be approved with a simple agreement, would take months. It would consume the Senate floor and paralyze the body from being able to take up almost any other action, aides say.

White House National Security Council Coordinator for Strategic Communications John Kirby blasted Tuberville's "ridiculous hold" on Thursday, telling CNN in an interview the move "is having an enormous effect already, four months in, and if he keeps doing it, it's going to have an even more dramatic effect going forward."

Cornyn, who is also on the GOP leadership team, told CNN that he has been discussing "other options" with Tuberville.

"I understand his point that the Department of Defense does not have the authority to do what it's doing, and I've been discussing with him other options he might have to accomplish his goal, but allow those nominations to go through," Cornyn said.

When asked if Tuberville seemed opened to the options, Cornyn responded, "He's talking to me, which is a good sign."

Tuberville says he has not received any direct pressure from McConnell, but in a news conference in May, McConnell made it clear to reporters that he did not support the Alabama Republican's hold.

Manchin also told CNN that he has also been "trying to talk him out of it," but did not expand on his conversations with Tuberville.

In recent weeks a number of other senators have also begun deploying the tactic of slowing down nominees for entire agencies as a way to prove a political point. Sen. Bernie Sanders, an independent who caucuses with the Democrats, has warned he will hold up nominees at the National Institutes of Health until more is done on drug pricing. Ohio Republican Sen. J.D. Vance announced this week he will hold up Department of Justice nominees in response to an indictment of former President Donald Trump.

"I am not really liking the direction things are going right now. We are starting to see more members that are saying, 'I am just going to do a blanket hold,'" Alaska Republican Sen. Lisa Murkowski said. "Are we all gonna start taking hostages now?"