WASHINGTON — The Justice Department instructed Robert Mueller, former special counsel, in a letter Monday not to answer a wide variety of questions about his investigation of the president and Russian interference in the 2016 election — a fresh indication of how difficult it may be to extract any new information or insights about the high-profile investigation when he testifies to Congress on Wednesday.

Associate Deputy Attorney General Bradley Weinsheimer said in Monday’s letter that he was responding to a request earlier this month from Mueller for guidance on how to handle questions ‘‘concerning privilege or other legal bars applicable to potential testimony in connection with’’ subpoenas for Mueller’s congressional testimony.


The letter also notes that Mueller had resisted testifying and that ‘‘the Department agrees with your stated position that your testimony should be unnecessary under the circumstances.’’

Weinsheimer then went on to spell out the categories of information that should be off-limits in Mueller’s testimony on Wednesday before two House committees. The Justice Department expects that Mueller will ‘‘not go beyond’’ the public version of his March report of his findings.

‘‘Please note there should be no testimony concerning the redacted portions of the public version of your report,’’ the letter said, and reminded Mueller that the prosecution of Trump adviser Roger Stone and a separate case are still awaiting trial, ‘‘and local court rules and specific orders issued in those cases substantially restrict the Department’s ability to make public statements about those cases.’’

The final portion of the letter makes a broader, vaguer admonition not to discuss matters that could be covered by executive privilege — a legally and factually complicated assertion that could, in theory, cover many topics, given that Mueller’s task was to investigate President Trump while working in the executive branch.

The letter defines potential executive-privilege-covered matters to include ‘‘information protected by law enforcement, deliberative process, attorney work product, and presidential communication privileges. These privileges would include discussion about investigative steps or decisions made during your investigation not otherwise described in the public version of your report.’’


The letter instructs Mueller to decline to discuss ‘‘potentially privileged matters’’ so that Justice Department lawyers can review the specific topics later and decide whether they are covered by executive privilege.

Earlier in the day, a spokesman for the former special counsel said Mueller does not intend to stray beyond what was detailed in his 448-page report.

Mueller, in fact, plans to submit the publicly available version of his report on Russian interference in the 2016 election as a statement for the record, the spokesman said.

‘‘His official statement for the record will be the Mueller report itself,’’ said Jim Popkin of the Seven Oaks Media Group, who was recently tapped to help Mueller handle media inquiries in advance of his congressional testimony.

Mueller will first appear before the House Judiciary Committee starting at 8:30 a.m. Wednesday. He will then appear before the House Intelligence Committee at noon.