The House Oversight Committee is threatening to hold a former White House official in contempt for ignoring a subpoena issued as part of their probe into abuses of the security clearance process.

Committee chair Elijah Cummings (D-MD) issued a statement Tuesday urging former White House personnel security director Carl Kline to testify instead of following the White House’s order not to do so.

“The White House and Mr. Kline now stand in open defiance of a duly authorized congressional subpoena with no assertion of any privilege of any kind by President Trump,” Cummings said. “Based on these actions, it appears that the President believes that the Constitution does not apply to his White House, that he may order officials at will to violate their legal obligations, and that he may obstruct attempts by Congress to conduct oversight.”

“I intend to consult with House Counsel and Committee Members about scheduling a vote on contempt,” he added. “I hope that Mr. Kline, in close consultation with his personal attorney, will carefully review his legal obligations, reconsider his refusal to appear, and begin cooperating with the Committee’s investigation.”

An attorney representing Kline told the committee on Monday that Kline would follow an order from the White House to ignore the subpoena. The White House demanded that Kline only be deposed by the committee if accompanied by a representative from the Office of Counsel to the President. After the committee rejected that demand, the White House told Kline to ignore the subpoena.

“The Committee has repeatedly deposed officials across the government — including from the White House — represented by their own counsel and excluding representatives of the agency under investigation,”Cummings said in his Tuesday statement. “The White House now seeks to stonewall this otherwise routine congressional process. There are obvious reasons we need to conduct our investigations of agency malfeasance without representatives of the office under investigation.”

Kline is accused of retaliating against a whistleblower who raised concerns that 25 people who were denied security clearances by career officials were then granted the clearances by political appointees. Kline allegedly placed files out of the reach of whistleblower Tricia Newbold, who has dwarfism, after she voiced her concerns.