FILE - In this July 10, 2018, file photo, President Donald Trump is joined by Gordon Sondland, the U.S. ambassador to the European Union, second from right, as he arrives at Melsbroek Air Base, in Brussels, Belgium. Sondland, wrapped up in a congressional impeachment inquiry, was a late convert to Trump, initially supporting another candidate in the Republican primary and once refusing to participate in a fundraiser on his behalf. (AP Photo/Pablo Martinez Monsivais, File) Associated Press

On Wednesday, EU Ambassador Gordon Sondland is to testify before the House impeachment inquiry.

He has before him a dilemma: whether to row back on testimony he gave earlier in the hearings which has now been ripped apart by other witnesses.

Sondland previously said he was not aware of a „quid pro quo“ offer to Ukraine to reinstate military aid in exchange for a criminal probe of Joe Biden and his son.

Others have since testified that Sondland did indeed know about this, and loudly discussed it in public.

He later revised his testimony to say that he did remember discussing a quid pro quo with Ukrainian officials.

If he sticks with his account, and lawmakers believe he is not telling them the truth, they can pursue perjury charges that carry the potential of a prison sentence.

If lawmakers believe that Sondland has lied to them, they can refer him to the Department of Justice for criminal prosecution on perjury charges.

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The witness whose testimony the White House is said to fear the most is scheduled to appear before the House impeachment inquiry on Wednesday.

Gordon Sondland, the multimillionaire hotel magnate and US ambassador to the EU, was one of small group of US officials who carved out the unofficial diplomatic backchannel with Ukraine which is the focus of the inquiry.

The group sought to broker a deal, offering to release frozen military aid and dangling a high profile White House trip to Ukraine’s newly elected president, Volodymyr Zelensky.

In exchange, they wanted a criminal investigation launched by Ukraine into Joe Biden, whose son Hunter had business dealings in the country.

Ahead of the testimony, Sondland faces a legal dilemma:

He could again revise the account he gave in his closed-door deposition in October 17 — which made no mention of Trump having a direct role in the scheme. This would likely attract the anger of the White House.

He could stick with his account, even though it has been contradicted by several other witnesses. If lawmakers go so far as to believe he is lying, they could pursue perjury charges and potentially see him jailed.

„If I was him, I would be very worried about a referral to the committee for a criminal charge and I would be trying to get on the right side of the committee to prevent that happening. The committee now has a lot of leverage over him to get him to tell the truth,“ Matthew Miller, a former Justice Department chief spokesperson, told The Guardian.

In his initial testimony, Sondland distanced himself from attempts to broker a „quid pro quo“ deal with Ukraine.

He said he had little contact with Trump, and didn’t know about the suspension of military aid, which it is claimed Trump officials offered to reinstate in exchange for the Biden probe.

David Holmes OLIVIER DOULIERY/AFP via Getty Images

He subsequently revised his testimony.

Sondland claimed to have since remembered that he told a close aide to Zelensky that the frozen US aid would not be released until Ukraine announced a probe into Burisma, the Ukrainian energy firm where Biden’s son, Hunter, served on the board.

The difference was dramatic, and his new account supports the „quid pro quo“ accusation on which much of the argument for impeaching Trump hinges.

Since then, a series of witnesses have exposed holes in Sondland’s testimony, or outright contradicted it.

In explosive testimony David Holmes, a senior official in the US embassy in Kyiv, on Friday told the inquiry that in a Kyiv restaurant on July 26 he overheard Sondland in a noisy public phone call with Trump.

Sondland, Holmes said, told Trump that Ukraine’s president „loves your ass,“ and was ready to launch the Biden probe. (No such probe was launched.)

During the live televised hearing, in front of millions of viewers worldwide, Democrats are almost certain to ask the ambassador why he did not mention the phonecall in either his initial or revised testimony.

Tweet Embed:

//twitter.com/mims/statuses/1195866990155579395?ref_src=twsrc%5Etfw

Sondland is in deep doo-doo.

He can ask Roger Stone how deep.

Perjury is serious.

Gordon Sondland Suddenly Remembered Perjury Is a Thing, Stephen Colbert Says https://t.co/03fJn4vQUD

He will also likely be grilled on other incidents omitted from earlier testimony, in which witnesses say he claimed to have been carrying out the president’s wishes in seeking the Biden probe deal.

This flatly contradicts his earlier statement to Congress, in which he claimed that he took part in „no discussions with any State Department or White House official about former Vice President Biden or his son.“

He also said he didn’t recall taking part in an effort to „encourage“ such a probe.

Evidence so far points to Sondland being in a better position than any other witness to directly tie the president Trump to the „quid pro quo“ deal Democrats are now describing as an act of bribery.

Speaking to The Washington Post, Republican Rep. Michael Conway of Texas, spelt out the legal jeopardy facing Sondland — portraying the real danger facing him as one in which he chose again to revise his account in light of other testimony.

„I expect Ambassador Sondland to tell us the same thing he said in his deposition,“ Rep. Conway told the publication.

Asked what would happen if he does not, he said: „Well, there are legal ramifications for that, for changing your [testimony]. He’s got to have good reasons.“