House Democrats subpoenaed President Donald Trump‘s personal lawyer Rudy Giuliani on Monday for documents pertaining to the effort to push Ukraine’s government to investigate Joe Biden. 

Three House committees sent requests for records to Giuliani and three of his associates allegedly involved in the Ukraine controversy, which has led Democratic lawmakers from Congress’s lower chamber to push for an impeachment inquiry into Trump.

Reps. Adam Schiff (D-California), Eliot Engel (D-New York) and Elijah Cummings (D-Maryland) — the respective chairmen of the House Intelligence, Foreign Affairs and Oversight Committees —  signed the letter addressed to Giuliani and his three associates: Igor Fruman, Lev Parnas and Semyon Kislin. The congressmen noted in the letter that they wished to schedule depositions with Giuliani’s partners in the upcoming weeks and that the former New York City mayor is required to comply with the subpoena by Oct. 15.

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“A growing public record indicates that the President, his agent Rudy Giuliani, and others appear to have pressed the Ukrainian government to pursue two politically-motivated investigations,” the letter read. “The committees have reason to believe that you have information and documents relevant to these matters.”

In an interview with Chris Cuomo on CNN earlier this month, Giuliani famously contradicted himself about ordering Ukraine’s government to probe Biden, Trump’s opponent in the 2020 election, and his son for alleged corruption. It was also reported last week that Trump asked Ukrainian President Volodymyr Zelensky to work with both Giuliani and Attorney General William Barr to investigate Biden. Schiff, Engel and Cummings pointed out Giuliani’s confession on CNN in their letter.

“In addition to this stark admission, you stated more recently that you are in possession of evidence — in the form of text messages, phone records, and other communications — indicating that you were not acting alone and that other Trump Administration officials may have been involved in this scheme,” the trio of congressmen added in their request.

In an interview on ABC’s This Week with George Stephanopoulos over the weekend, Giuliani said he would refuse to cooperate with Schiff and House Democrats on the Ukraine controversy. The former New York City mayor also said in a separate interview that he would only be willing to testify before Congress about the issue if he secured Trump’s approval to do so.