Here are the Trump associates who have been subpoenaed in the impeachment inquiry

House Democrats issued their first subpoena of the Trump impeachment inquiry to Secretary of State Mike Pompeo.

Pompeo was the first administration official to be subpoenaed on September 27 in the Democratic-led impeachment proceedings in late September.

According to The New York Times, the subpoena parallels earlier document requests that House Democrats had already issued. They demanded a full transcript of the July 25 phone call between Trump and the Ukrainian president, a list of all State Department officials who heard or received any summaries of the call.

The Wall Street Journal recently reported Pompeo took part in the call, likely making him a key figure in the Democratic-led investigation.

Pompeo, however, forcefully pushed back against their demand for documents. The secretary of state said in a tweet that he was "concerned with aspects" of the request from House Democratic leaders "that can be understood only as an attempt to intimidate, bully, & treat improperly the distinguished professionals of the Department of State."

Trump's personal lawyer Rudy Giuliani was also subpoenaed in the impeachment inquiry.

House Democrats also subpoenaed Giuliani in late September after reports emerged he was at the heart of Trump's efforts to pressure Ukraine into investigating one of the president's leading political rivals.

Congressional investigators ordered Giuliani to furnish communications and documents going back to early 2017 by October 15. The Associated Press reported it encompasses "text messages, phone records and other communications" as well as business records and depositions from three of Giuliani's associates, some of whom gathered information on his behalf on the Bidens in the Ukrainian capital of Kiev.

"Your failure or refusal to comply with the subpoena, including at the direction or behest of the president or the White House, shall constitute evidence of obstruction of the House's impeachment inquiry and may be used as an adverse inference against you and the president," the letter read.

Giuliani criticized the subpoena in an interview with The Times. "We're getting really close to, if we haven't met, the standard of the McCarthy hearings where nobody seems to care about things like attorney-client privilege," he said.

A subpoena landed at the White House on October 4, widening the impeachment inquiry

House Democrats threw a subpoena at the White House for all Ukraine-related documents. In a letter addressed to acting White House Chief of Staff Mick Mulvaney, they demanded all documents related to the July 25 phone conversation, the halting of aid delivery to Ukraine, and any efforts by Giuliani or his associates to pressure the Ukrainians to investigate the Bidens.

"The White House has refused to engage with — or even respond to — multiple requests for documents from our Committees on a voluntary basis. After nearly a month of stonewalling, it appears clear that the president has chosen the path of defiance, obstruction, and cover-up," the letter read. It ordered the furnishing of the documents by October 18.

White House Press Secretary Stephanie Grisham downplayed the subpoena's significance and blasted the impeachment proceedings as "kangaroo courts."