Witness Giuliani? What the latest evidence tells us about Trump's lawyer

On the eve of the House delivering impeachment articles to the Senate, explosive new evidence surfaced that links President Donald Trump’s lawyer Rudy Giuliani to an apparent effort to track the physical movements of a female U.S. ambassador including texts by one man who refers to the “bitch” who should be fired and inquires cryptically about people inside Ukraine willing to help for “a price.”

While Giuliani does not appear to be directly involved in the alleged surveillance, his connections to the men involved raise serious questions about whether his efforts in Ukraine put a high-ranking American official at risk.

The evidence also could put fresh pressure on senators to demand new witnesses – possibly even Giuliani himself -- in the upcoming Senate impeachment trial despite objections by Republican Majority Leader Mitch McConnell, who favors a swift acquittal for Trump.

If called to testify, Giuliani would likely be questioned about his conversations with Trump -- what the president knew and when -- and the extent to which he kept other top aides like Secretary of State Mike Pompeo in the loop.

Giuliani has previously said he would testify in the Senate trial and that he would like to try the case himself. But when asked about that possibility on Wednesday, Giuliani suggested he wouldn't have much to say because he is the president's lawyer.

“I am bound by attorney client privilege so it’s not just my decision," Giuliani told ABC News.

At issue is new evidence released Tuesday and Wednesday by the House Intelligence Committee that was provided by Lev Parnas, a Ukrainian American businessman and associate of Giuliani’s who has been arrested on campaign finance violations.

According to notes scratched out by Parnas on stationary from the Ritz Carlton in Vienna, Parnas was on board with Giuliani’s efforts to try to get Ukraine President Volodymyr Zelenskiy to announce an investigation involving former Vice President Joe Biden.

He also was working to try to oust Marie Yovanovitch, the top U.S. diplomat in Ukraine.

While the new evidence does not name Yovanovitch, the ambassador has testified that she was aware Parnas was trying to force her ouster, possibly so he could work with individuals the U.S. State Department regarded as corrupt.

In one particularly disturbing text exchange from March 2019 – one month before Yovanovitch said she was recalled from her post due to security concerns -- a Connecticut man and Trump donor named Robert F. Hyde texted Parnas: “Wow. Can’t believe Trump hasn’t fired that bitch. I’ll get right in that.”

Both Parnas and Hyde have dismissed the text exchange as not serious. In an interview with MSNBC's "The Rachel Maddow Show," Parnas accused Hyde of being "drunk all the time." Hyde said in a tweet this week that he was never in Kyiv and that he and Parnas "were playing" while "we had a few drinks."

“The guys over they asked me what I would like to do and what is in it for them,” Hyde said on March 25, later adding details like “her phone is off” and that she is “next to the embassy” with “privacy security.”

“They are willing to help if we/you would like a price,” Hyde writes. “Guess you can do anything in the Ukraine with money … what I was told.”

Parnas responds: “Lol.”

The next day, Hyde provides an update and asks: “If you want her out they need to make contact with security forces.”

Parnas eventually responds that he will call him.

The left-leaning watchdog group, American Oversight, notes that social media posts suggest the text exchanges coincide with a dinner between Parnas and Giuliani, and phone calls between Giuliani and Secretary of State Mike Pompeo.

Reached by ABC News, Hyde decline to comment on the messages. But when asked if he was offering to harm the ambassador, he said “absolutely not.”

Larry Robbins, a lawyer for Yovanovitch, called the allegations "disturbing" in a statement and that the ambassador hopes the “appropriate authorities” will investigate. Ukrainian officials have said they are investigating.

Several witnesses have testified that the president ordered a hold on $400 million in security assistance to Ukraine, despite clearance from the Pentagon and State Department. And when asked about U.S. aid in general on a July phone call, Trump asked Ukraine’s president for a “favor” and called for an investigation into Biden.

Still unclear though is whether Trump directed his top aides to continue withholding the aid – money needed to fend off Russian aggression at Ukraine’s borders – until it announced the probe naming Biden.

The White House has said Parnas isn't a credible witness and shouldn't be taken seriously. His media interviews though beg the question of whether the Senate should demand more evidence to understand what happened, before making the fateful decision of whether to remove the president from office.

Parnas said there was no doubt the president and his top aides orchestrated the pressure campaign to extract a political favor.

"President Trump knew exactly what was going on" with his activities in Ukraine, Parnas told MSNBC's Maddow.

ABC News' Katherine Faulders contributed to this report.