The challenges to acting Attorney General Matthew Whitaker's recent appointment keep coming.
Sens. Richard Blumenthal, Mazie Hirono and Sheldon Whitehouse said in a statement that because Whitaker wasn't confirmed by the Senate, his appointment violates the U.S. Constitution.
It's the same argument that's surfaced recently from critics of President Donald Trump's pick to oversee the agency following former Attorney General Jeff Sessions' ouster.
Last week, the Justice Department released a memo defending the appointment. According to the DOJ, because Whitaker is only serving on a temporary basis, there's no Senate confirmation requirement.
The decision to select Whitaker has sparked concerns about special counsel Robert Mueller's Russia investigation, as both Trump and Whitaker have expressed disapproval of the probe.
So far, the DOJ hasn't responded to the latest suit.
Additional reporting from Newsy affiliate CNN.