Chairmen of three House committees leading the impeachment inquiry of President Donald Trump on Friday demanded Vice President Mike Pence turn over documents related to the president’s campaign to pressure Ukraine for political objectives, including records from Energy Secretary Rick Perry and the department he runs.

The Department of Energy did not respond immediately to a request for comment.

[Trump contends ‘no quid pro quo’ with Ukraine is ‘whole ballgame’ on impeachment]

In a letter, the chairmen told Pence refusal to comply with the request, which calls for the production of files from multiple cabinet departments, would “constitute evidence of obstruction” of the House’s impeachment inquiry.

“The Committees are investigating the extent to which President Trump jeopardized national security by pressing Ukraine to interfere with our 2020 election and by withholding security assistance provided by Congress to help Ukraine counter Russian aggression, as well as any efforts to cover up these matters,” the letter says.

Reps. Eliot L. Engel, chairman of the Foreign Affairs Committee; Adam B. Schiff, chairman of the Intelligence Committee; and Elijah E. Cummings, chairman of the Oversight and Government Reform Committee, sent the letter. They gave Pence until Oct. 15 to fulfill their request.

While Perry has remained unscathed in the impeachment investigation, the letter makes plain House Democrats view Perry as a key figure in their inquiry.

Multiple news organizations reported Thursday Perry plans to resign by the end of November. An Energy Department spokeswoman denied to CQ Roll Call that Perry plans to leave. 

[jwp-video n=”1″]

The Democrats demand Pence supply records about telephone conversations on April 21 and July 25 and several government agencies, including the Energy Department and current and former officials there. 

They also want Pence to turn over records about a May 23 meeting at the White House involving Trump, Perry, former U.S. special envoy to Ukraine Kurt Volker and Gordon Sondland, U.S. ambassador to the European Union.

Sen. Robert Menendez, ranking member of the Senate Foreign Relations Committee, asked Perry on Tuesday about the trip he led to Ukraine on May 20, when he attended the inauguration of Ukrainian President Volodymyr Zelenskiy.

Neither Perry nor the department have commented or responded publicly about the letter.

The House investigators demanded files on the Ukraine trip, as well as two others: a July 10 White House meeting with Ukrainian and American officials, including Perry; and a separate meeting in Warsaw, Poland, on or around Sept. 1.

Separately in their request, the chairmen demanded Pence turn over government records on the potential blocking of government funding to Ukraine from U.S. agencies, including the Energy Department.

Correction 8:23 p.m. | An earlier version of this story misstated Kurt Volker’s former position.