A group of Senate Democrats has filed a lawsuit in U.S district court arguing that President Donald Trump’s appointment of Matt Whitaker as acting attorney general is unconstitutional.

According to a Monday Daily Beast report, Sens. Richard Blumenthal (D-CT), Sheldon Whitehouse (D-RI) and Mazie Hirono (D-HI) are suing on the grounds that Whitaker was not Senate-confirmed for the post.

Trump appointed Whitaker through the Vacancies Reform Act, which allows for temporary staffing for 210 days. But the senators are citing a common claim among constitutional scholars that the act does not give the President license to slot a non-confirmed person into a Cabinet-level position.

Whitaker was confirmed by the Senate 14 years ago for his job as a U.S. attorney in Iowa, but some argue that the confirmation has expired.

Last week, the state of Maryland filed a court challenge against Whitaker’s legitimacy as head of the DOJ on similar grounds, arguing that Trump cannot “bypass the constitutional and statutory requirements for appointing someone to that office.”

The DOJ penned a memo in response, claiming that Trump’s move falls within the bounds of the Constitution.