The state of Maryland is poised to file a court challenge against acting Attorney General Matt Whitaker’s legitimacy as head of the Justice Department and his ability to oversee special counsel Robert Mueller probe, The New York Times reported Tuesday.

Maryland is planning to ask a federal judge to issue an injunction placing attorney general authority in the hands of Deputy Attorney General Rod Rosenstein. In a draft of the filing obtained by the Times, the state of Maryland plans to argue that Trump can’t “bypass the constitutional and statutory requirements for appointing someone to that office.” The Maryland legal challenge against Whitaker builds on a lawsuit the state filed against former Attorney General Jeff Sessions. Since Sessions is no longer head of the DOJ, a federal judge would have to rule on who his successor legally is, according to the Times.

However, the Justice Department’s Office of Legal Counsel is expected to issue a memo this week in defense of Whitaker’s appointment and Trump’s authority to make that appointment, according to The Wall Street Journal and CNN. The memo will reportedly argue that guidance issued in 2003 about former President George W. Bush’s decision to appoint a non-confirmed staffer as interim head of the Office of Management and Budget authorizes Trump to make the same call, WSJ reported.

DOJ office of legal counsel will issue memo defending Trump appointment of Whitaker pic.twitter.com/kg5GVz3SkE — TPM Livewire (@TPMLiveWire) November 13, 2018

Democrats have been up in arms over Whitaker’s appointment as acting attorney general, given his past public disparagement of Mueller and the Russia probe. House Democrats have already begun investigating the circumstances surrounding Sessions ouster and Whitaker’s appointment. Senate Minority Leader Chuck Schumer (D-NY) sent a letter asking the White House to explain why Whitaker — an “unconfirmed political appointee” — was named to the post.