The move, announced in a letter from the Justice Department, comes right before the Committee is set to vote on whether to hold Attorney General William Barr and Commerce Secretary Wilbur Ross in contempt of Congress for refusing to turn over the materials. 

The committee is investigating whether the decision by the Trump administration to add a citizenship question to the 2020 census was politically motivated. 

Assistant Attorney General Stephen Boyd notified Committee Chairman Elijah Cummings (D-MD) that "the Attorney General is now compelled to request that the President invoke executive privilege with respect to the materials subject to the subpoena," and as such "the President has asserted executive privilege over certain subpoenaed documents identified by the Committee in its June 3, 2019 letters to the Attorney General and the Secretary."