House Democrats circulated an internal memo Tuesday rebutting Republican talking points in defense of 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 as the lower chamber's impeachment investigation ramps up into a public phase on Wednesday.

The document, which was obtained by The Hill, comes after Republicans outlined their strategy to defend the president by focusing on "four key pieces of evidence" they say are "fatal" to Democrats' allegations about Trump's dealings with Ukraine.

ADVERTISEMENT

The memo rebuts GOP arguments that there was no pressure on a July 25 call between Trump and Ukrainian President Volodymyr Zelensky to investigate former Vice President Joe Biden Joe BidenFormer Pence aide: White House staffers discussed Trump refusing to leave office Progressive group buys domain name of Trump's No. 1 Supreme Court pick Bloomberg rolls out M ad buy to boost Biden in Florida MORE, that Ukraine was not aware of a hold on $400 million in military aid to Kyiv, and that Democrats’ allegations that the funds hinged on the probe into Biden are moot since the aid was ultimately released.

The Democrats' memo says there was clearly pressure leveraged on Zelensky during the July call, citing a rough transcript released by the White House showing that Trump repeatedly mentioned his desire for Kyiv to work with 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, Trump’s personal attorney, and Attorney General William Barr Bill BarrFederal prosecutor speaks out, says Barr 'has brought shame' on Justice Dept. Why a backdoor to encrypted data is detrimental to cybersecurity and data integrity FBI official who worked with Mueller raised doubts about Russia investigation MORE to investigate Biden on unfounded corruption allegations. Additionally, the memo cites several witnesses who have already testified behind closed doors that they felt there was a pressure campaign to link the aid to the inquiry.

The memo also cites two officials who testified that Ukraine was in fact aware of the hold on the aid.

“I knew from my 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 conversations and also from sort of the alarm bells that were coming from Ambassador Taylor and his team that there were Ukrainians who knew about this,” the memo cites Laura Cooper, a top Defense official who oversees Ukraine, as testifying, referring to other officials involved in the investigation.

Democrats finally note that the military aid to Kyiv was released only after members of Congress expressed alarm over the hold.

The memo comes a day before the House is set to hold its first public hearings in its impeachment investigation. William Taylor, the top U.S. diplomat to Ukraine, and George Kent, a top State Department official, are set to testify Wednesday, while former U.S. Ambassador to Ukraine Marie Yovanovitch is expected to testify Friday.

House Democrats launched their impeachment inquiry in September over concerns that Trump threatened to withhold the military funds to Zelensky unless he publicly launched an inquiry into Biden and 2016 election meddling. Republicans have dismissed concerns that Trump’s request was inappropriate, arguing he was working to make sure taxpayer dollars were properly spent in a country known for corruption.

However, several witnesses have testified that they were uncomfortable with Trump’s request and that they believed there was a quid pro quo surrounding the president’s dealings with Ukraine.