As the House impeachment inquiry has moved from closed depositions to open hearings, lawmakers largely knew what witnesses would say. But Gordon Sondland, the U.S. ambassador to the European Union who will testify Wednesday, is a cliffhanger.

The House Intelligence Committee will hear from Sondland after three days of testimony with seven other witnesses, many of whom spoke to conversations they’ve had with him. Those accounts place Sondland in the center of the controversy about whether Trump withheld security assistance to Ukraine and a White House meeting with the country’s new president to secure investigations into his political rivals.

Neither Democrats nor Republicans seem to trust Sondland or can predict exactly what he’ll say. But he is the cooperating witness with the most direct interactions with Trump on Ukraine.

Sondland amended his testimony from an Oct. 17 closed-door deposition, saying in a Nov. 4 addendum that other witness statements had refreshed his memory. Since then, a new witness has come forward about a phone call he overheard between Sondland and Trump that the ambassador never referenced in his deposition or addendum.

A Republican donor whom Trump nominated for his ambassadorship despite no prior diplomatic experience, Sondland testified about direct calls he made to the president. Other witnesses testified that Sondland had a close relationship with Trump, but the ambassador guessed he had only spoken to the president five or six times since his confirmation.

One such interaction was a May 23 White House meeting in which he and other officials returning from Ukrainian President Volodymyr Zelenskiy’s inauguration briefed Trump. Trump directed the officials, who were urging him to meet with Zelenskiy, to talk to his personal lawyer, Rudy Giuliani, but was not specific as to what about, Sondland testified.

Sondland said he first spoke to Giuliani in August and learned Trump wanted Zelenskiy to make a public statement about “anti-corruption issues.”

“Giuliani specifically mentioned the 2016 election, including the DNC server, and Burisma as two anti-corruption investigatory topics of importance for the president,” Sondland said, referring to unsubstantiated allegations that Kyiv intervened in the 2016 election and a Ukrainian gas company. Sondland did not recall Giuliani mentioning former Vice President Joe Biden or his son Hunter, who served on Burisma’s board. 

“My understanding was that the president directed Mr. Giuliani’s participation and that Mr. Giuliani was expressing the concerns of the president,” he said.

‘No quid pro quo’

Sondland said Trump never linked the release of U.S. security assistance that was being withheld to the investigations. When William Taylor, the acting U.S. envoy to Ukraine, expressed his impression that the aid was conditioned on the investigations, Sondland said he called Trump.

“I asked the president, ‘What do you want from Ukraine?’” Sondland said. “The president responded, ‘Nothing. There is no quid pro.’ The president repeated, ‘no quid pro.’”

Sondland acknowledged he didn’t know whether Trump was telling the truth.

“President Trump changes his mind on what he wants on a daily basis,” he said. “I have no idea what he wanted on the day I called him. That’s why I asked him the question.”

Other witnesses, like Taylor and Tim Morrison, the former National Security Council director for Europe and Russia policy, testified to conversations with Sondland in which he linked the security assistance to the investigations.

After reading their opening statements, Sondland offered an addendum to testimony saying that since he had no “credible explanation” for the suspension of the aid he “presumed” it was linked to Ukraine investigations.

Taylor and Morrison’s closed-door testimony also prompted Sondland to recall a conversation in which he told Zelenskiy adviser Andriy Yermak after a Sept. 1 bilateral meeting between Vice President Mike Pence and Zelenskiy in Warsaw that the aid likely wouldn’t be released until Ukraine made a public commitment to the investigations.

New information

The call in which Sondland said Trump stated he did not want a quid pro quo occurred about a week later, on Sept. 9. But a new witness has come forward to testify that Sondland and Trump discussed the investigations on July 26, the day after Trump’s call with Zelenskiy in which he asked the Ukrainian to open probes into 2016 and Burisma.

David Holmes, a foreign service officer who works for Taylor at the U.S. Embassy in Ukraine, told congressional investigators in a closed-door deposition Friday that he overheard a conversation between Sondland and Trump while he was at lunch with Sondland after they and other U.S. diplomats held a series of meetings July 26 with Zelenskiy and his aides in Ukraine.

According to Holmes, Sondland in briefing Trump on the meetings told the president that Zelenskiy “loves your ass.” Holmes said he could hear Trump respond because he was speaking so loudly that Sondland had to hold the phone away from his ear, adding that the president also asked, “So he’s going to do the investigation?”

“He’s going to do it,” Sondland responded, saying Zelenskiy will “do anything you ask him to,” according to Holmes, who didn’t take notes but said the call was “so remarkable that I remember it vividly.”

Holmes said after the call he asked Sondland for his impression about Trump’s views on Ukraine, specifically questioning “if it was true that the president did not give a s— about Ukraine.”

Sondland agreed, saying Trump only cares about “big stuff” that benefits him like the “Biden investigation” that Giuliani was pushing, according to Holmes.

Holmes’ testimony contradicts Sondland’s deposition, in which he told lawmakers he didn’t recall talking to Giuliani about investigations until August and even then didn’t remember references to the Bidens.

‘Don’t know what to expect’

What Sondland says Wednesday is anyone’s guess.

“I don’t know what to expect,” Intelligence Chairman Adam B. Schiff said Monday on “Pod Save America.” 

As the only witness the House committees have interviewed who had multiple conversations with Trump about Ukraine, Sondland is in a position to vindicate the president or throw him under the bus. (The committees sought testimony from others close to Trump, but those witnesses have heeded White House orders not to comply.)

“The whole impeachment effort will focus primarily on one witness, and that’s Ambassador Sondland and what he says or doesn’t say on Wednesday,” said North Carolina Republican Rep. Mark Meadows, a member of the Oversight Committee and one of Trump’s most vocal defenders. 

Democrats, who have already raised questions about whether Sondland was truthful in his deposition, hope he will learn from the experiences of  other Trump associates prosecuted for lying to Congress.

“Look, it was not lost on Ambassador Sondland what happened to the president’s close associate, Roger Stone, for lying to Congress, to [former Trump lawyer] Michael Cohen for lying to Congress,” senior House Intelligence member Jim Himes said on “Fox News Sunday,” referring to Stone and Cohen’s felony convictions. 

Schiff also referenced Stone and Cohen’s convictions, saying those cases demonstrate that Congress takes perjury “very seriously.”

To turn or not to turn

Republicans think as long as Sondland sticks to the script from deposition, the facts he presents will help the president.

“At this particular point, we have no reason to believe that he’s going to go back against a deposition that he gave and then revised,” Meadows said.

Rep. Lee Zeldin, another Trump defender, said Sondland’s firsthand account is better than other witnesses who are testifying to secondhand or thirdhand information provided to them through Sondland. But the New York Republican does have questions about Sondland’s use of “presumption” in his addendum.

“If the president told him, as he said in the deposition, that there’s no quid pro quo and that the president said he didn’t expect anything from Ukraine, then why would you use the word ‘presume’?” he said.

Sondland is one of the witnesses Democrats chose to call for the open hearings, but his testimony is a bit of a risk for them since he largely shielded Trump from blame during his deposition.

“They have to either get him to turn on the president or attack his credibility,” Meadows said. 

Attacking Sondland’s credibility is also risky because, as Meadows put it, “All the other testimony has a Sondland core to it.”

Some Democrats have already started the discrediting.

“Gordan Sondland is a Trump flunky who may have already committed perjury, so we’ll see what he does when he shows up on the Hill,” House Democratic Caucus Chairman Hakeem Jeffries told CQ Roll Call. “But he’s not going to make things any better for Donald Trump. If anything, it’ll be worse.”

Asked if Sondland was credible, Rep. Jamie Raskin quoted Mark Twain: “If you always tell the truth, you never have anything to remember.”

“There are some witnesses who seem to be constantly scrambling to go back and see what they said and to revise their remarks,” the Maryland Democrat said.

Sondland may want to use his testimony Wednesday to put questions about his credibility to rest, but it will be difficult to defend his own reputation and the president’s at the same time.

Whichever path he chooses may be critical to his employment. Sondland is still an ambassador who serves at the pleasure of the president. If he says anything to anger Trump, he could be attacked, or even fired, by tweet in real time.

Raskin said Sondland’s direct interactions with Trump put him at risk of such attacks, much like Cohen was because of his position “in the Trump hemisphere.”

Those witnesses aren’t the most reliable, Raskin said, explaining it this way: “When I was a prosecutor for a few years, they used to say, ‘You don’t go into a sewer looking for swans.’”