One of Donald Trump's top allies is changing his tune.

Gordon Sondland, the United States ambassador to the European Union, recently submitted a three-page declaration in which he admitted to sending a quid pro quo message to Ukrainian officials, marking a stunning reversal from his previous testimony. According to the addendum released by House impeachment investigators Tuesday, Sondland claims his recollection of "certain conversations" were "refreshed" after reviewing statements from National Security Council official Tim Morrison and U.S. ambassador to Ukraine William Taylor.

Sondland described a Sept. 1 conversation with Andriy Yermak about the suspension of $391 million in U.S. military aid to Ukraine. Sondland said he told Yermak, a top aide to Ukrainian President Volodymyr Zelensky, that the "aid would likely not occur until" Ukrainian officials publicly announced an investigation into the Bidens. This, of course, is bad news for Trump, as it confirms a U.S. official had told Ukraine that the Congress-approved aid package was contingent on an investigation into Trump's political opponent. Basically, Sondland confirmed a quid pro quo. 

"I always believed that suspending aid to Ukraine was ill-advised, although I did not know (and still do not know) when, why, or by whom the aid was suspended," he wrote. "However; by the beginning of September 2019, and in the absence of any credible explanation for the suspension of aid, I presumed that the aid suspension had become linked to the proposed anti-corruption statement."

"After that large meeting, I now recall speaking individually with Mr. Yermak, where I said that resumption of U.S. aid would likely not occur until Ukraine provided the public anti-corruption statement that we had been discussing for many weeks."

The testimony was part of the impeachment inquiry launched by Democrats last month. The probe stems from an intelligence whistleblower complaint filed by an intelligence officer, who was concerned that Trump was "using the power of his office to solicit interference from a foreign country in the 2020 US election." A transcript of a July 25 phone call between POTUS and Zelensky supports the quid pro quo allegations, as Trump encouraged the Ukrainian president to investigate Joe Biden and his son, Hunter Biden—specifically, the latter's position on the board of Ukrainian energy company Burisma Holdings.

"The other thing, There's a lot of talk about Biden's son, that Biden stopped the prosecution and a lot of people want to find out about that so whatever you can do with the Attorney General would be great," Trump said, according to the transcript. "Biden went around bragging that he stopped the prosecution so if you can look into it ... It sounds horrible to me.

Trump has denied any quid pro quo in pressuring Ukraine to investigate the 2020 democratic presidential candidate and his son.

You can read Sondland's declaration below.