House Democrats are considering taking dramatic steps to protect the anonymity of a whistleblower who filed a complaint against President Donald Trump, The Washington Post reported Monday.

The official is preparing to testify before Congress, and The Post reports that Democrats are weighing allowing the person to testify at a remote, off-site location away from Capitol Hill.

They're also said to be debating over shielding the person's face and appearance.

Democrats are considering these measures, officials told The Post, because they're afraid President Donald Trump's congressional allies will leak the whistleblower's identity to the public.

At the heart of the whistleblower's complaint is a July 25 phone call Trump had with Ukrainian President Volodymyr Zelensky, during which he repeatedly pressured Zelensky to investigate former Vice President Joe Biden and his son.

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House Democrats are worried that President Donald Trump's congressional allies will leak the identity of the anonymous whistleblower behind the Ukraine complaint and are considering taking dramatic steps to protect that person, The Washington Post reported Monday.

In particular, Democrats are said to be weighing letting the whistleblower testify to Congress at a remote location away from Capitol Hill. They're also debating over masking the person's voice and face, according to The Post.

The news is indicative of the extraordinary stakes at play as lawmakers prepare to hear from the whistleblower, a CIA officer whose complaint accused Trump of violating federal law and using his public office for private gain.

At the heart of the controversy is a July 25 phone call Trump had with Ukrainian President Volodymyr Zelensky, during which Trump repeatedly pressured Zelensky to investigate former Vice President Joe Biden and his son on suspicion of corruption. Biden is a 2020 Democratic presidential frontrunner and one of Trump's chief political rivals.

Trump ordered his administration to withhold a nearly $400 million military-aid package to Ukraine days before the phone call.

While the White House's notes of the call show the US president made no direct mention of offering aid in exchange for Zelensky's assistance in investigating Biden, they confirm Trump brought up how the US did "a lot for Ukraine" right before asking Zelensky to do him a "favor, though," by investigating Biden and discrediting the former special counsel Robert Mueller's Russia investigation.

In addition to accusing Trump of abusing his power and violating federal law, the complaint says that Trump's personal lawyer, Rudy Giuliani, is a "central figure" in Trump's effort and that Attorney General William Barr "appears to be involved as well."

Trump's handpicked spy chief testified to Congress that the complaint was "in alignment" with the notes of the call.

The intelligence community watchdog also deemed the complaint to be "urgent" and "credible." Last week, Trump confirmed the complaint's central allegation — that he wanted a foreign government to investigate a political opponent — when he publicly called for both Ukraine and China to look into the Bidens.

Despite the public evidence supporting the whistleblower's allegations — much of which came from either Trump or the White House — the president and his allies have accused the official of committing espionage. Trump has also suggested the whistleblower and the officials they learned their information from are guilty of treason.