House Democrats announced Wednesday that they will hold their first public impeachment hearings next week, marking an escalation of their investigation into President Trump Donald John TrumpFederal prosecutor speaks out, says Barr 'has brought shame' on Justice Dept. Former Pence aide: White House staffers discussed Trump refusing to leave office Progressive group buys domain name of Trump's No. 1 Supreme Court pick MORE's dealings with Ukraine.

Intelligence Committee Chairman Adam Schiff (D-Calif.) said that lawmakers initially plan to call in three witnesses as Democrats begin making their case to the public that Trump pressured a foreign power to investigate political opponents.

Schiff said that William Taylor, the top U.S. diplomat to Ukraine, and George Kent, a top State Department official, will testify next Wednesday. Former U.S. Ambassador to Ukraine Marie Yovanovitch is then expected to testify next Friday.

ADVERTISEMENT

Democrats have been moving towards holding public hearings this month as they shift the impeachment inquiry to a public phase after initially holding a series of depositions behind closed doors with current and former administration officials.

The House voted last week largely along party lines to pass a measure outlining the procedures for impeachment, and Democrats this week released a series of transcripts of the previous closed-door depositions, including Yovanovitch's transcript on Monday.

Yovanovitch had testified last month about a concerted effort led by Rudy Giuliani Rudy GiulianiThe Hill's Campaign Report: GOP set to ask SCOTUS to limit mail-in voting CIA found Putin 'probably directing' campaign against Biden: report Democrats fear Russia interference could spoil bid to retake Senate MORE, the president's personal lawyer, to remove her from her diplomatic post. According to transcripts released this week, Yovanovitch told investigators how Giuliani worked outside government channels in a multipronged effort to oust her.

"I thought that this was a dangerous precedent, that as far as I could tell, since I didn't have any other explanation, that private interests and people who don't like a particular American ambassador could combine to, you know, find somebody who was more suitable for their interests," she testified on Oct. 11, according to the transcript. "It should be the State Department, the President, who makes decisions about which ambassador."

Yovanovitch, a career diplomat, was removed from Ukraine in May. But following Trump’s July 25 phone call with Ukrainian President Volodymyr Zelensky — in which Trump referred to the former ambassador as "bad news" — Yovanovitch said she felt her career and her pension were threatened.

"I hate to be repetitive, but I was shocked," she said when describing the decision.

Yovanovitch also told House investigators that Trump officials carried out a campaign to pressure Ukrainian leaders to investigate former Vice President Joe Biden, a leading contender in the 2020 presidential race.

"And, obviously, the President did make a decision," she added, "but I think influenced by some who are not trustworthy."

Kent, who serves as the deputy assistant secretary of State, also previously testified about efforts to oust Yovanovitch as well as a campaign to pressure Zelensky into opening probes desired by Trump, according to a Democratic lawmaker at the time.

Rep. Gerry Connolly Gerald (Gerry) Edward ConnollyJudge issues nationwide injunction against Postal Service changes House panel advances bill to ban Postal Service leaders from holding political positions Shakespeare Theatre Company goes virtual for 'Will on the Hill...or Won't They?' MORE (D-Va.) said after Kent testified last month that the State Department official voiced concerns with what he described as an informal alliance between several figures wrapped up in the Ukraine affair who worked in concert to oust Yovanovitch and press Ukrainian leaders to investigate the Bidens for the purpose of boosting Trump's reelection chances next year.

Schiff, who made a short public statement Wednesday, said the committee expects to also release Taylor’s testimony later in the day.

Taylor, who serves as the chargé d’affaires for Ukraine, tied Trump officials to a secretive shadow foreign policy campaign in his leaked opening remarks, saying that they sought to obtain a public statement about investigations into the 2016 presidential election and Burisma, a Ukrainian energy company that employed former Biden’s son, Hunter.

Taylor’s testimony, which Democrats described at the time as one of the most powerful they had heard, is expected to build on his 15-page opening statement, in which he laid out in meticulous detail the decisions by Trump and others to withhold roughly $400 million in financial aid until he secured commitment from Ukraine to open the politically charged investigations.

As more and more officials have testified about what they consider to be a quid pro quo surrounding Trump's dealings with Ukraine, Republicans are leaning on another witness, Kurt Volker Kurt VolkerGOP senators request details on Hunter Biden's travel for probe Yovanovitch retires from State Department: reports Live coverage: Senators enter second day of questions in impeachment trial MORE, the former envoy to Ukraine, who they think exonerated Trump with his account delivered on Oct. 3.

The transcript of Volker's closed-door testimony, released Tuesday, revealed that the former career diplomat had told lawmakers that the hold on military aid was “not significant” to U.S.-Ukrainian relations.

"The definitive account on all this is the one from Ambassador Volker," Rep. Jim Jordan James (Jim) Daniel JordanHouse panel pulls Powell into partisan battles over pandemic Sunday shows preview: Justice Ginsburg dies, sparking partisan battle over vacancy before election House passes resolution condemning anti-Asian discrimination relating to coronavirus MORE (Ohio), the senior Republican on the Oversight Committee, told reporters in the Capitol on Wednesday. "He was the special envoy to Ukraine; he was the guy who was in this each and every day working on these issues."

Rep. Scott Perry Scott Gordon PerryOn The Trail: How Nancy Pelosi could improbably become president GOP lawmaker: Systemic racism doesn't exist and there's 'more to the story' of Floyd's death We're united in an effort to end the FDA's dog testing mandate MORE (R-Pa.), another Trump ally, took that argument a step further, suggesting Volker is the only fully reliable witness to testify thus far in the investigation.

"He seems to be the one honest broker in the whole thing that has a long-standing relationship with not only the position but with the two countries," Perry said.

Republicans quickly lamented that Volker was not on Schiff's early invitation list for next week’s public hearings. But Jordan said Republicans are readying their own witness list, to be assembled by Rep. Devin Nunes Devin Gerald NunesOvernight Defense: Stopgap spending measure awaits Senate vote | Trump nominates former Nunes aide for intelligence community watchdog | Trump extends ban on racial discrimination training to contractors, military Trump nominates former Nunes aide to serve as intel community inspector general Sunday shows preview: Justice Ginsburg dies, sparking partisan battle over vacancy before election MORE (R-Calif.), the ranking member of the Intelligence Committee.

Rep. Mark Meadows Mark Randall MeadowsWhite House chief of staff knocks FBI director over testimony on election fraud Anxious Democrats amp up pressure for vote on COVID-19 aid Pelosi hopeful COVID-19 relief talks resume 'soon' MORE (R-N.C.) said the GOP’s wish-list would likely extend beyond the cast of officials who have already testified privately in the probe. He also declined to say if Hunter Biden was on that list.