The House Committees on Intelligence, Foreign Affairs, and Oversight subpoenaed Ambassador to the European Union Gordon Sondland to hand over Ukraine-related documents and appear at a deposition in a letter Tuesday. The committees gave Sondland until Oct. 14 to hand over the requested documents, and have compelled him to appear before lawmakers on Oct. 16. Sondland was supposed to appear before Congress on Tuesday, but the State Department ordered him to avoid the hearing just hours beforehand. President Trump tweeted that Sondland would not be appearing to testify because Congress had turned into a “totally compromised kangaroo court.”

Sondland is considered a key witness to Trump's dealings with Ukraine, which took center stage after a whistleblower filed a complaint about a July 25 call between Trump and the Ukrainian president that sparked an impeachment inquiry. Trump's personal attorney, Rudy Giuliani, told The Daily Beast he had briefed Sondland about his progress in pushing for Ukraine to investigate corruption allegations against ex-Vice President Joe Biden and his son. Sondland also reportedly took part in drafting a statement for Ukraine that would hold them accountable to investigate the Bidens.