The House Committee on Oversight and Government Reform is set to vote on a measure approving the subpoena of the former White House director responsible for approving government clearances.

Committee Chairman Elijah Cummings, D-Md., is preparing to advance the motion in a full committee session on Tuesday of next week, saying that the motion falls in line “with the Committee’s investigation into the security clearance process at the White House.”

Since House Democrats took the majority, the committee has been investigating the process by which the White House issues security clearances to its employees after concerns that unqualified individuals inside the White House have access to confidential information.

Last month, the Oversight Democrats launched a committee investigation after reports surfaced that Trump directed officials to grant high-level clearance to Jared Kushner, Trump's son-in-law and a White House senior aide. Former national security adviser Michael Flynn and former White House staff secretary Rob Porter are also said to be subjects of the committee's probe.

Cummings sent a letter last month to White House counsel Pat Cipollone saying that the committee is fully prepared to issue subpoenas to former and current White House officials if the administration does not comply with the committee's requests for documents.

In response, Cipollone argued that the committee is making “unprecedented and extraordinarily intrusive demands," saying that the White House has sole discretion on the approval of clearance requests.

He said that the "decision to grant or deny a security clearance is a discretionary function that belongs exclusively to the Executive Branch.”

Cummings has also renewed the committee's efforts to obtain documents from Commerce Secretary Wilbur Ross pertaining to the added citizenship question on the 2020 census.

"The requested documents and interviews may provide contemporaneous evidence of the real reason that you added the citizenship question and the process you followed," Cummings' Friday letter to the Department of Commerce said.

A Commerce Department representative said the agency has been responsive to the committee.

“The Department has delivered over 11,000 pages of documents pertaining to the Committee’s request and the Secretary himself voluntarily testified for nearly seven hours on these issues two weeks ago," the representative said. "The Department has cooperated in good faith with the Committee and will look to do so in the future.”