President Trump on Wednesday asserted executive privilege over subpoenaed materials related to the House Oversight Committee's investigation into a 2020 Census citizenship question.

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."

Boyd added that the DOJ has "repeatedly informed the Committee that a limited subset of the documents is protected from disclosure," citing attorney-client privilege among the reasons.

Cummings has delayed the contempt vote until later Wednesday so that members of the committee could read the DOJ's letter, according to Axios, though he slammed what he called was "blanket defiance" from the Trump administration.

"The DOJ’s letter says that they were prepared to produce additional documents responsive to the subpoena. But they make clear, very clear, that they will not produce the key documents that we have identified as priorities. This does not appear to be an effort to engage in good faith negotiations or accommodations. Instead, it appears to be another example of the administration’s blanket defiance of Congress’s constitutionally mandated responsibilities.” -Elijah Cummings

It is unclear what will happen after the committee's Wednesday vote. According to CNN "House Democrats could go to the floor with both criminal and civil contempt. They could also drop criminal before going to the floor if some accommodation happens."

Read the DOJ letter below: