Congressional Democrats on Thursday slapped Energy Secretary Rick Perry with a subpoena for what they called “key documents” in the impeachment inquiry of President Trump.

A nine-page letter from Rep. Adam Schiff (D-Calif.), Rep. Elijah Cummings (D-Md.) and Rep. Eliot Engel (D-NY) cites news reports that link Perry to the July 25 phone call in which Trump sought a Ukrainian probe into allegations that former Vice President Joe Biden had “stopped the prosecution” in that country of his son, Hunter.

“On Oct. 4, 2019, President Trump reportedly ‘told House Republicans that he made his now infamous phone call to Ukrainian President Volodymyr Zelensky at the urging of Energy Secretary Rick Perry – a call Trump claimed he didn’t even want to make,’ ” the letter says.

The letter notes that Perry attended Zelensky’s May 2019 inauguration and cites a CNN report that said Trump, during a May 23 Oval Office meeting, told Perry and State Department officials “to deal with his private attorney Rudy Giuliani when the Ukrainian President sought to meet Trump, in a clear circumvention of official channels.”

It also cites an Associated Press report that said Perry pressured Zelensky to purge the advisory board of Ukraine’s state-owned Naftogaz oil and gas company at the behest of Trump donors including Lev Parnas and Igor Fruman, two associates of Giuliani’s who were busted Thursday on federal campaign-finance charges.

The Democrats demanded records needed to review “these events and the reasons behind the White House’s decision to withhold critical military assistance to Ukraine that was appropriated by Congress to counter Russian aggression.”

They gave Perry until Oct. 28 to hand over the documents and warned that failure to do so, “including at the direction or behest of the President or the White House, shall constitute evidence of obstruction of the House’s impeachment inquiry.”

Neither the Energy Department nor the White House immediately returned requests for comment.

In a Tuesday letter, White House Counsel Pat Cipollone told House Democrats that Trump and his administration wouldn’t cooperate with their impeachment inquiry, saying it “lacks any legitimate constitutional foundation, any pretense of fairness, or even the most elementary due process protections.”