WASHINGTON (AP) — Escalating his fight against Congress’ impeachment inquiry, President Donald Trump flouted Democratic warnings about impeachable conduct Tuesday in blocking a U.S. diplomat from testifying about Trump’s dealings with Ukraine. House committee chairmen quickly declared they would subpoena the envoy to force him to appear.

Gordon Sondland, the U.S. European Union ambassador, was barred by the administration from appearing in a closed-door session with three House panels investigating Trump’s entreaties to Ukraine. Text messages released last week revealed conversations between Sondland and two other U.S. diplomats who were acting as intermediaries as the president urged Ukraine to investigate the 2016 U.S. election and a gas company linked to Joe Biden’s family.

House intelligence committee Chairman Adam Schiff said Sondland’s no-show was “yet additional strong evidence” of obstruction of Congress by Trump and Secretary of State Mike Pompeo, Sondland’s boss.

“By preventing us from hearing from this witness and obtaining these documents, the president and secretary of state are taking actions that prevent us from getting the facts needed to protect the nation’s security,” Schiff said. “For this impeachment inquiry we are determined to find answers.”

House Speaker Nancy Pelosi echoed Schiff’s comments at an event in Seattle, saying it was an “abuse of power” for Trump to thwart witness testimony.

Democrats believe that Sondland, who donated $1 million to Trump’s election effort in 2016, could provide valuable information. He spoke to Trump in September as diplomats raised questions about why security aid to Ukraine was being withheld. After the call, Sondland assured another diplomat in a text message, as Trump has insisted in the past days, that there was “no quid pro quo’s of any kind” with Ukraine.

Schiff, House Foreign Affairs Chairman Eliot Engel and House Oversight and Government Reform Chairman Elijah Cummings said they would subpoena Sondland for testimony and also for documents — including additional communications on a personal device that he has turned over to the State Department. Schiff said the department is withholding those communications.

Sondland’s absence on Tuesday raised questions about whether other witnesses called by the committee would appear. Marie Yovanovitch, the former U.S. ambassador to Ukraine who was recalled from the post, is scheduled to testify Friday, and the committee has called two other State Department officials.

Trump indicated on Tuesday morning that it was his own decision to stop the deposition, tweeting that he would “love to send Ambassador Sondland” to testify, “but unfortunately he would be testifying before a totally compromised kangaroo court.”

Sondland’s attorney said in a statement that his client was “profoundly disappointed” that he wasn’t able to talk to the committees.

Democrats have struggled to investigate Trump and his administration all year as the White House has blocked and ignored subpoenas for documents and testimony. While the Democrats are already in court to force some of that evidence, they are making it clear that they do not intend to wait much longer. Articles of impeachment, including for obstruction, could be drafted by the end of the year.

Speaking to reporters Tuesday, Schiff laid out four parameters of the committee’s investigation. He said the panel is probing whether Trump solicited foreign help from Ukraine for his 2020 reelection, whether a never-realized White House meeting between Ukrainian President Volodymyr Zelenskiy and Trump was conditioned on the country conducting investigations, whether U.S. military assistance to Ukraine was conditioned on those investigations and whether the administration has obstructed justice.

Top Republicans generally have criticized Schiff and defended the president. Ohio Rep. Jim Jordan said Tuesday that Trump was simply “doing his job” to prevent corruption in Ukraine.

Across the Capitol, Senate Judiciary Committee Lindsey Graham — one of Trump’s staunchest defenders — said he would call the president’s personal lawyer, Rudy Giuliani, to testify about corruption in Ukraine. Giuliani was communicating with Zelenskiy about the investigations that Trump wanted.

“Given the House of Representatives’ behavior, it is time for the Senate to inquire about corruption and other improprieties involving Ukraine,” Graham said in a tweet.

In response, Giuliani said he was “very interested” in Graham’s invitation but said he would need “to review” matters of executive privilege and attorney-client privilege before committing to appear.

House Democrats have subpoenaed Giuliani for documents, but Giuliani said he would not cooperate with them.

Text messages released by House Democrats last week show Sondland working with another of Trump’s diplomats, former Ukrainian envoy Kurt Volker, to get Ukraine to agree to investigate any potential interference in the 2016 U.S. election and also to probe the Ukrainian energy company that appointed Biden’s son Hunter to its board. In exchange, the American officials dangled the offer of a Washington meeting between Trump and Zelenskiy.

There has been no evidence of wrongdoing by Biden or his son.

Among the most striking messages was the one in which Sondland sought to reassure a third diplomat that their actions were appropriate and then added: “I suggest we stop the back and forth by text.”

Sondland reached out to Trump because he was concerned by the alarms raised by the other ambassador, William “Bill” Taylor, the charge d’affaires at the U.S. Embassy in Ukraine, according to a person familiar with the exchange. The person insisted on anonymity to discuss the conversation.

Separately on Tuesday, lawyers for House Democrats urged a judge to release secret grand jury testimony from special counsel Robert Mueller’s Trump-Russia investigation, arguing that it is needed for the impeachment inquiry.

The outcome may turn on whether the judge is convinced the House is conducting an official impeachment inquiry. The distinction matters because while grand jury testimony is ordinarily secret, one exception authorizes a judge to disclose it in connection with a judicial proceeding such as impeachment.

Republicans argue that impeachment is not underway because the House has not voted on starting an investigation.

(Copyright (c) 2023 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)

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