House Intelligence Committee member Rep. Denny HeckDennis (Denny) Lynn HeckExclusive: Guccifer 2.0 hacked memos expand on Pennsylvania House races Heck enjoys second political wind Incoming lawmaker feeling a bit overwhelmed MORE (D-Wash.) said Friday that there is no reason for the White House to defy a congressional subpoena for Ukraine-related documents unless President TrumpDonald John TrumpGordon Sondland expected to appear for House deposition Ivanka Trump on impeachment: 'Everything's a question of priorities' Second intel official considering filing complaint over Trump: report MORE is "guilty."

Asked what would happen if the White House doesn't comply with the subpoena, Heck told CNN, "Defiance of this act constitutes obstruction of a legitimate congressional inquiry in pursuit of impeachment, and as a consequence of that we will presume or infer that he is not innocent of whatever it is that we're out to verify with the documentation."

"There is no other reason for him to withhold it, to hide it, unless of course he's guilty," he added, referring to Trump. 

.@RepDennyHeck explains the "incredibly damning" evidence facing Trump:
"The call report, the President's own words, in which he said... 'I need you to do us a favor, though,' and that combined with what Ambassador Taylor said about it being crazy to withhold security assistance" pic.twitter.com/Fj90ySt1nC

— OutFrontCNN (@OutFrontCNN) October 4, 2019

House Democrats earlier Friday issued a subpoena to the White House requesting documents related to the president's dealings with Ukraine. Committees also sent a request to Vice President Pence for documents as their impeachment probe heats up.

“We deeply regret that President Trump has put us—and the nation—in this position, but his actions have left us with no choice but to issue this subpoena,” House Intelligence Committee Chairman Adam SchiffAdam Bennett SchiffSecond intel official considering filing complaint over Trump: report Trump mocks Schiff with Pinocchio-themed video Democrats claim new momentum from intelligence watchdog testimony MORE (D-Calif.), Oversight and Reform Committee Chairman Elijah CummingsElijah Eugene CummingsOvernight Defense: House Dems subpoena White House for Ukraine documents | Pence pulled into inquiry | GOP senator says he confronted Trump over Ukraine aid | Iran hackers target 2020 campaign House Democrats subpoena White House for Ukraine documents House panels seek Ukraine docs from Pence for Trump impeachment inquiry MORE (D-Md.) and Foreign Affairs Committee Chairman Eliot EngelEliot Lance EngelOvernight Defense: House Dems subpoena White House for Ukraine documents | Pence pulled into inquiry | GOP senator says he confronted Trump over Ukraine aid | Iran hackers target 2020 campaign House Democrats subpoena White House for Ukraine documents House panels seek Ukraine docs from Pence for Trump impeachment inquiry MORE (D-N.Y.) wrote to acting White House chief of staff Mick MulvaneyJohn (Mick) Michael MulvaneyOvernight Defense: House Dems subpoena White House for Ukraine documents | Pence pulled into inquiry | GOP senator says he confronted Trump over Ukraine aid | Iran hackers target 2020 campaign House Democrats subpoena White House for Ukraine documents Ex-senior Trump administration official joins lobbying shop MORE.

In their letter, they also warned that defiance of the subpoena would be used as evidence of obstruction. They have given the White House until Oct. 18 to produce the documents. 

The White House said in a statement Friday night that the subpoena "changes nothing – just more document requests, wasted time, and taxpayer dollars that will ultimately show the President did nothing wrong."

"The Do Nothing Democrats can continue with their kangaroo court while the President and his Administration will continue to work on behalf of the American people," White House press secretary Stephanie GrishamStephanie GrishamHouse Democrats subpoena White House for Ukraine documents Trump approves Poland's entry to visa waiver program Trump: Democrats wasting time on 'bulls---' with impeachment inquiry MORE added in the statement.

Last week, Democrats launched an impeachment inquiry into Trump's dealings with Ukraine, largely based on a call in which Trump encouraged Ukrainian President Volodymyr Zelensky to "look into" Democratic presidential candidate Joe BidenJoe BidenGordon Sondland expected to appear for House deposition Ivanka Trump on impeachment: 'Everything's a question of priorities' Second intel official considering filing complaint over Trump: report MORE.

Trump has maintained that his actions were proper while blasting criticism from the few GOP figures who have raised concerns about his efforts.