House Democrats on Wednesday threatened to subpoena White House officials for records on President Donald Trump’s discussions with Ukraine as part of their formal impeachment inquiry into the president’s phone call with the eastern European country’s president, Volodymyr Zelensky.

“Over the past several weeks, the committees tried several times to obtain voluntary compliance with our requests for documents, but the White House has refused to engage with—or even respond to—the committees,” House Oversight Committee chairman Elijah Cummings (D-MD) wrote in a memo, according to the New York Times.

Cummings warned that Democrats will authorize the subpoenas if the White House fails to comply with the request for records by Friday.

“The White House’s flagrant disregard of multiple voluntary requests for documents —combined with stark and urgent warnings from the Inspector General about the gravity of these allegations — have left us with no choice but to issue this subpoena,” the lawmaker stated.

The subpoena will be directed toward acting chief of staff Mick Mulvaney and request 13 separate batches of documents related to the July call and other related matters. The call unfolded against the backdrop of a $250 million foreign aid package for Ukraine that was being readied by Congress but stalled by Trump.

White House Press Secretary Stephanie Grisham said the subpoena is “nothing but more document requests, wasted time and taxpayer dollars that will ultimately show the president did nothing wrong.”