Giuliani's claims, for which he has provided no evidence, cut against the sworn testimony of several State Department officials and diplomats who characterized Yovanovitch as an anti-corruption champion and consummate professional before the president summarily removed her after Giuliani's urging.

The former New York City mayor's statements also suggest he was much more influential in Trump's decision to pull Yovanovitch than the president and his allies have publicly admitted — and that he was motivated to seek her ouster because she stood in the way of Trump's favored political investigations.

Trump invited Giuliani to the White House last week, just days after Giuliani returned from a trip to Kyiv and began reviving allegations against Yovanovitch and Trump's political adversaries.

Trump has confirmed he's spoken to Giuliani and welcomed any information his attorney might provide to the Justice Department and Congress. The president has also retweeted some of Giuliani's allegations about Yovanovitch.

No impeachment investigators of either party have questioned Yovanovitch's integrity, despite the continuing attacks by Giuliani. Yovanovitch testified last month that at least two of the prosecutors Giuliani met with were enablers of corruption and that they would have viewed her as an obstacle because of her efforts to root it out.

Separately, accusations of perjury in congressional investigations are extremely difficult to prove because they require showing not only that witnesses made false statements, but that they did so intentionally and in a way that materially impacted the inquiry.

In his volley of attacks, Giuliani also claimed that the embassy under Yovanovitch "stopped a Ukrainian audit of over $5 billion in aid funding put in question in 2017 by Ukrainian auditors,” and warned there was “plenty more” information to come that would further detail unfounded allegations of corruption against Yovanovitch.

Giuliani has repeatedly spoken out in recent days on his role in fomenting the Ukraine scandal that has imperiled Trump’s presidency, pouring gasoline on a charge for which the House is preparing to impeach his client this week.

“I believed that I needed Yovanovitch out of the way,” Giuliani told The New Yorker in a story published Monday. “She was going to make the investigations difficult for everybody.”

Appearing Monday on Fox News, Giuliani said of Yovanovitch: “I didn’t need her out of the way. I forced her out because she’s corrupt.”

And in an interview Monday evening with The New York Times, Giuliani said he told the president “a couple of times” earlier this year how Yovanovitch was impeding investigations that could benefit Trump, who proceeded to connect Giuliani with Secretary of State Mike Pompeo.

Trump recalled Yovanovitch from Kyiv in April following a smear campaign by Giuliani and his associates baselessly accusing the longtime foreign service officer of disloyalty to the White House and of attempting to interfere in Ukraine’s justice system.

Yovanovitch described the circumstances surrounding her abrupt departure during a public hearing of the House Intelligence Committee last month, telling lawmakers that she did “not understand Mr. Giuliani’s motives for attacking me.”