Sen. Lisa Murkowski (R-Alaska) announced Thursday afternoon that she will vote against Pete Hegseth, President Trump’s nominee to serve as secretary of Defense, citing his past infidelity and allegations of sexual assault and excessive drinking.

Murkowski in a statement posted to X said she had “significant concerns” about his nomination.

She said that managing the Pentagon “requires vast experience and expertise” and that Hegseth’s prior career roles “do not demonstrate to me that he is prepared for such immense responsibility.”

She also cited the numerous allegations of misconduct against Hegseth.

“While the allegations of sexual assault and excessive drinking do nothing to quiet my concerns, the past behaviors Mr. Hegseth has admitted to, including infidelity on multiple occasions, demonstrate a lack of judgment that is unbecoming of someone who would lead our armed forces,” Murkowski said.

“These behaviors starkly contrast the values and discipline expected of servicemembers,” she added.

The Senate is set to vote on cloture for Hegseth’s nomination Thursday afternoon, setting up a likely final vote on Friday. He advanced out of the Senate Armed Services Committee on a party-line vote.

Hegseth has forcefully denied the allegation that he sexually assaulted a woman in 2017 and denied claims that he mismanaged the finances of two veterans groups he led before becoming a Fox News contributor and later a Fox News anchor.

He called many of the anonymous allegations against him part of a “smear” campaign against his nomination.