House Democrats led by Rep. Adam B. Schiff of California, chairman of the Intelligence Committee, issued a sweeping subpoena Monday to President Donald Trump’s personal lawyer Rudolph Giuliani, asking him to preserve and produce documents relating to his dealings with Ukraine dating back to January 2017.

The subpoena also seeks documents and depositions from Giuliani’s associates Lev Parnas, a Ukrainian businessman; the latter’s partner Igor Fruman; and Semyon Kislin, a Russian businessman who is said to be associated with Giuliani. The documents are due to the House Democrats by Oct. 15.

[McConnell says he can’t completely prevent an impeachment trial]

The House Intelligence, Foreign Affairs, and Oversight and Reform committees are jointly conducting an impeachment inquiry. The probe stems from a whistleblower’s complaint that Trump pressured Ukrainian President Volodymyr Zelensky during a July 25 phone call for help in probing former Vice President Joseph R. Biden Jr., potentially in exchange for U.S. military assistance to Ukraine.

Schiff, along with Foreign Affairs Chairman Elliot L. Engel of New York and Oversight Chairman Elijah E. Cummings of Maryland, noted in a statement that Giuliani acknowledged on CNN that “while serving as the President’s personal attorney, he asked the government of Ukraine to target former Vice President Joe Biden.”

“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 House Democrats wrote to Giuliani.

The subpoena lists about two dozen items including documents, conversations with associates, work done by Giuliani with Ukrainian entities, and details of phone calls between Trump and Ukrainian officials and other U.S. Cabinet agencies.