Ms. Pelosi was not ready to say whether she will follow suit, but left the door open. “The president is obstructing Congress from getting the facts that we need,” she told reporters in Seattle, where she was holding an unrelated event. “It is an abuse of power for him to act in this way.”
Even before the White House released its letter, Mr. Trump signaled his defiance on Tuesday, ridiculing the inquiry as spurious.
“I would love to send Ambassador Sondland, a really good man and great American, to testify,” the president wrote on Twitter Tuesday morning around the time Mr. Sondland was to appear, “but unfortunately he would be testifying before a totally compromised kangaroo court, where Republican’s rights have been taken away.”
The decision to block Mr. Sondland from being interviewed was delivered at the last minute, after the ambassador had already flown to Washington from Europe, and lawmakers had returned from a two-week recess to observe the questioning. Mr. Sondland’s lawyers told House staff members that a State Department official left a voice mail message at 12:30 a.m. directing him not to appear.
Representative Adam B. Schiff, Democrat of California and the chairman of the House Intelligence Committee, told reporters that the State Department was also withholding text messages Mr. Sondland had sent on a private device that were “deeply relevant” to the inquiry. By the end of the day, House leaders issued a subpoena ordering Mr. Sondland to appear next Wednesday and turn over documents before then.
Mr. Sondland, a wealthy hotelier and contributor to Mr. Trump’s campaign, has become a central figure in the saga of the president’s efforts to seek political help from Ukraine. Although Ukraine is not in the European Union, Mr. Trump instructed Mr. Sondland to take a lead in his administration’s dealings with the country.
Mr. Sondland interacted directly with Mr. Trump, speaking with the president several times around key moments that House Democrats are now investigating, including before and after Mr. Trump’s July 25 call with President Volodymyr Zelensky of Ukraine. The president asked Mr. Zelensky in that conversation to “do us a favor” and investigate former Vice President Joseph R. Biden Jr. and conspiracy theories about Ukrainian involvement in the 2016 election.