Washington (CNN) House Judiciary Chairman Jerry Nadler called the Justice Department "incredibly arrogant" Tuesday for directing former special counsel Robert Mueller to adhere to the 448-page report he issued earlier this year during his upcoming testimony before the committee.

On Monday, the Justice Department, in a letter signed by Associate Deputy Attorney General Bradley Weinsheimer and sent to Mueller, said that the former special counsel "must remain within the boundaries of your public report because matters within the scope of your investigation were covered by executive privilege" during his hearing before the House committee on Wednesday morning. The letter was sent in response to Mueller's request for guidance about his testimony.

"I don't think it's much of an impediment simply because Bob Mueller had indicated repeatedly that he was going to do exactly that. I think it's incredibly arrogant of the department to try to instruct him as to what to say. It's a part of the ongoing cover-up by the administration to keep information away from the American people," Nadler told CNN's Alisyn Camerota on "New Day."

Nadler, a New York Democrat, added that he doesn't think the department's letter will "have a real impact" on Mueller's testimony.

"He does not have to comply with that letter -- he doesn't work for them. And that letter asks things that are beyond the power of the agency to ask even if he still worked for them," he said.

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