Graham (R-S.C.) violated Senate rules and standards of conduct because he was in a Senate office building when he did the interview, the bipartisan leaders of the ethics panel said in a rare public letter released Thursday.

“The public must feel confident that Members use public resources only for official actions in the best interests of the United States, not for partisan political activity,” wrote Senate Ethics Committee Chairman Chris Coons (D-Del.) and Sen. James Lankford (R-Okla.), the panel’s Republican vice chairman. “Your actions failed to uphold that standard, resulting in harm to the public trust and confidence in the United States Senate. You are hereby admonished.”

Coons and Lankford wrote that Graham solicited campaign contributions for Georgia Senate candidate Herschel Walker’s campaign committee “five separate times” during the Nov. 30 interview on Fox News. They noted that Graham reported himself to the committee after the interview was over.

In a statement Thursday, Graham said: “It was a mistake. I take responsibility. I will try to do better in the future.”

It is unclear if Graham could face any criminal penalties for his actions. Coons and Lankford said this was the senator’s second violation, after he similarly solicited campaign contributions for his own campaign during an unplanned hallway interview in 2020.

The ethics committee dismissed that complaint and notified Graham in a private letter, Coons and Lankford wrote. The panel did not publicly reveal that violation until now, having determined at the time that his conduct was ”inadvertent, technical, or otherwise of a de minimis nature,” the letter said.

The prohibitions on campaign solicitation in federal buildings and the use of federal resources for campaign activity “have been consistent and clear throughout your years of Senate service,” they wrote, and Graham solicited the campaign contributions in the November interview “despite the Committee’s specific guidance following your violation in October 2020.”