As Gordon Sondland, the former Portland hotelier now serving as the U.S. Ambassador to the European Union, prepares to testify before a House impeachment panel Oct. 17, the Washington Post is reporting Sondland's testimony may diverge from the White House's party line.

"Sondland's testimony will raise the possibility that Trump wasn't truthful in his denial of a quid pro quo," the Post reported.

As the Post previously reported, text messages Congress released recently showed that Sondland told another diplomat working with him on communications with Ukrainian officials earlier this year that President Donald Trump wanted "no quid pro quo's (sic) of any kind."

The significance of that claim is that in his text message, Sondland appeared to be denying that Trump intended to condition the release of $391 million in U.S. aid and a visit to the White House for Ukrainian officials on their willingness to investigate Hunter Biden and his father, former Vice President Joe Biden.

The House impeachment investigation centers on whether Trump was in fact attempting to use U.S. resources—the monetary aid and a visit to the White House—to convince the Ukrainians to probe whether Joe Biden improperly pushed for the firing of a Ukrainian prosecutor and for them to look into the circumstances of Hunter Biden's lucrative position with a Ukrainian energy company.

The existence of such an investigation—whether it turned up anything or not— would likely damage Joe Biden, Trump's leading opponent in the 2020 presidential election, and could reflect a use of U.S. resources for Trump's personal political benefit.

Now, as Sondland provides testimony after the State Department initially ordered him not to do so, Sondland may be moving away from the man who nominated him to his diplomatic position.

"Sondland plans to tell lawmakers he has no knowledge of whether the president was telling him the truth at that moment. 'It's only true that the president said it, not that it was the truth,' said the person familiar with Sondland's planned testimony, who spoke on the condition of anonymity to discuss sensitive diplomatic matters,'" the Post reported.

Sondland declined to be interviewed for the Post article and his personal attorney, Jim McDermott, says he'll have no comment until okayed by the administration.