Defense Secretary Pete Hegseth used a second Signal chat to discuss last month’s airstrikes in Yemen with his wife, brother and personal lawyer, sources told ABC News on Sunday.

In response, Sen. Tammy Duckworth of Illinois called for him to “resign in disgrace” in a statement on Sunday.

“How many times does Pete Hegseth need to leak classified intelligence before Donald Trump and Republicans understand that he isn’t only a f***ing liar, he is a threat to our national security?” Duckworth said.

Sen. Jack Reed of Rhode Island, the top Democrat on the Senate Armed Services Committee, also issued a statement on Sunday, saying that he has “grave concerns about Secretary Hegseth’s ability to maintain the trust and confidence of U.S. servicemembers and the Commander-in-Chief.”

Reed called on the Department of Defense’s Office of the Inspector General to include this incident in its ongoing investigation of Hegseth’s handling of classified information.

“If true, this incident is another troubling example of Secretary Hegseth’s reckless disregard for the laws and protocols that every other military servicemember is required to follow. He must immediately explain why he reportedly texted classified information that could endanger American servicemembers’ lives on a commercial app that included his wife, brother, and personal lawyer,” Reed said.

-ABC News’ Allison Pecorin