The ranking Democrat on the House Oversight and Government Relations Committee is demanding that Chairman Darrell Issa (R-Calif.) apologize for suggesting former Secretary of State Hillary Clinton may have told the Pentagon to stand down in the Benghazi attack response.

Rep. Elijah Cummings (D-Md.) took issue with a Monday speech Issa gave in New Hampshire. Issa told the GOP event he “came here to hopefully shape the debate for 2016.”

“We need to have an answer of when the secretary of Defense had assets that he could have begun spinning up. Why there was not one order given to turn on one Department of Defense asset?” Issa said of Benghazi. “I have my suspicions, which is Secretary Clinton told Leon [Panetta] to stand down, and we all heard about the stand down order for two military personnel. That order is undeniable.”

Cummings told Issa in a letter today that the “accusations are beyond the pale, and you should immediately retract them and issue a public apology.”

“The definition of treason is the betrayal of allegiance owed to one’s country, and your statements seem to accuse former Secretary Clinton of this offense. You suggest that Secretary Clinton directed the Secretary of Defense of the United States to intentionally withhold military assistance that may have saved the lives of one of her own ambassadors and three other brave Americans serving their country,” Cummings continued. “Attempting to qualify your accusations as ‘suspicions’ does not help your cause, but instead reveals that you have no evidence to back up your claims.”

He highlighted a recent House Armed Services Committee report that found there was no stand-down order, and added that he was “personally stunned by the reckless, baseless, and utterly offensive accusations you launched” against Clinton.

“This is not the first time you have publicly—and falsely—accused former Secretary Clinton of actions relating to Benghazi.  On April 24, 2013, you went on national television and accused Secretary Clinton of making false statements to Congress about personally authorizing security reductions in Libya, citing her ‘signature’ on a cable sent by the Department in 2012,” Cummings continued. “In fact, the cable you referenced—which you had access to at the time, but the press did not—included only a stamp of the Secretary’s name, like millions of other cables sent from the State Department to posts around the world.”

“Although you have frequently made baseless accusations without evidence to support them, I believe the statements you made on Monday in New Hampshire are the most insulting and unpatriotic accusations you have made during your past three years as Chairman. You may believe this kind of affront is acceptable at a political event with donors who expect rhetoric with ‘red meat,’ but Members of Congress have a higher and more solemn responsibility to respect the Constitution and those charged with fulfilling its mission. As the Ranking Member of this Committee, I ask that you publicly apologize for your statements and withdraw them immediately.”

Earlier this month, Issa told The Hill that he was retracting some comments: past praise for Clinton’s cooperation with the Benghazi investigation, as noted in a December 2012 interview for the book HRC: State Secrets and the Rebirth of Hillary Clinton.

“The snapshot in time was an accurate snapshot — at that time I had a pledge from the secretary to cooperate,” Issa said. “Secretary Clinton promised me full cooperation. I got less than full cooperation. She didn’t deliver.”

Issa also stressed that the probe is not over and Clinton will be called to answer the committee’s questions either in an open hearing or behind closed doors.

“She’s a factor in this in a number of areas,” he said. “In the case of Secretary Clinton, I do believe that there will be a number of questions that we will need to get specifically from her. I believe the same of [former] Secretary [of Defense Leon] Panetta.”