Sen. Claire McCaskill pushed back Thursday against personal criticisms regarding her military sexual assault proposal, amid a growing wave of support for an alternative proposal offered by Sen. Kirsten Gillibrand.

Momentum appears to be behind Gillibrand’s proposal, which would move the decision over whether to prosecute a sexual assault case outside of the chain of command. McCaskill’s proposal would keep the decision within the chain of command, and force higher ranking officials to review a case if the decision is made not to prosecute.

“Common sense will tell you: If you’ve been victimized and you go back to your unit, do you think it’s more likely you’re going to get retaliation if a bunch of outside lawyers decide to [prosecute] or if a commander [does]?” McCaskill, D-Mo., said at a Capitol press conference, flanked by retired female military officers, as well as Sens. Kelly Ayotte, R-N.H. and Jon Tester, D-Mont.

Gillibrand’s office told the Washington Examiner that they now had 44 senators publicly supporting her proposal. They need 51 senators for their amendment to pass. On Wednesday, Sens. Mark Kirk, R-Ill., and Michael Bennet, D-Colo., joined her amendment as co-sponsors.

Supporters of Gillibrand’s alternate proposal, in particular a group which advocates on behalf of military sexual assault victims, have recently taken aim at McCaskill, characterizing her personally as a “roadblock” to effective reform.

In advertisements both online and in a Missouri newspaper, the organization Protect Our Defenders singled out McCaskill as a target. St. Louis resident and sexual assault victim Terri Odom wrote in a letter to the St. Louis Post-Dispatch that McCaskill was “wrong regarding the reforms most urgently required to end the crisis of military rape… Without your support, perpetrators may continue to go free; victims will be too afraid to come forward; and our military readiness will suffer.”

For McCaskill, it’s a surprise attack from an organization with which she has previously coordinated. In March, Protect Our Defenders praised both McCaskill and Gillibrand’s “leadership” in “tackling the epidemic of sexual assault in the military.”

“The notion that I would ever be a roadblock to more aggressive prosecution is enough to give me a stomachache, but I understand that this is emotional issue,” McCaskill said Thursday, adding that those who support Gillibrand’s proposal may be “confused” about what the two approaches accomplish.

McCaskill’s frustration over the issue boiled over last week, when she told the country’s highest-ranking military officer, Gen. Martin Dempsey, that she would be “in front of the line to kick you until you’re senseless” if the problem of sexual violence was not better addressed.

The two sexual assault proposals showcase two different approaches to combating the problem. Gillibrand’s approach hands the decision to prosecute a case to an independent body, while McCaskill’s approach keeps the decision within the military hierarchy.

The Pentagon has adamantly opposed Gillibrand’s proposal, arguing that to change the military’s culture, commanders need to be involved in the process.

Meanwhile, aides on both sides of the debate insist that there is no personal animosity between the senators leading the charge on competing proposals.

“Sens. Gillibrand and McCaskill have been working closely together on a number of reforms to combat the epidemic of sexual assault in the military. While they may not agree on every reform, they share the same goals,” Gillibrand spokeswoman Bethany Lesser said.

In fact, a handout distributed at Thursday’s press conference emphasized the multitude of reforms that both Gillibrand and McCaskill agree on, pointing out that they are united on more sexual assault reforms than they disagree on.

The Senate Armed Services Committee added McCaskill’s provision to the Defense Authorization Act, and rejected Gillibrand’s proposal. Gillibrand is expected to bring up her amendment again when the legislation comes before the whole Senate later this year.