On Saturday, US President Donald Trump in a tweet demanded that Schiff step down, accusing the House Intel Chair of modifying the recently-released transcript of Trump's July phone call with Ukrainian President Volodymyr Zelensky.
Hours later, Trump tweeted again, claiming that Schiff made a "totally fraudulent statement to the House and public".
In a series of tweets on Saturday, Trump fired back at accusations that he pressed the Ukrainian president to probe the business activities of former US Vice President Joe Biden's son in Ukraine, in an alleged bid to tarnish his potential political opponent during the upcoming presidential election in the US - accusations that were used by House Dems to introduce an impeachment inquiry against Trump.
Trump earlier called on Schiff to be investigated over what the former called a fictitious account of his phone conversation with Zelensky.
House Democrats launched an impeachment inquiry based on a whistleblower complaint alleging presidential misconduct in the 25 July telephone conversation between Trump and Zelensky.
The complaint additionally accuses the White House of attempting to restrict access to the transcript of one of the telephone conversations between the presidents, while describing the phone conversation between the two as a bid by Trump - in pressing Zelensky to probe former Vice President Joe Biden - to solicit a foreign power to interfere in the 2020 US presidential election.
The White House subsequently declassified an unredacted transcript of the phone conversation.
The transcript revealed that Trump asked Zelensky to work with the former's personal lawyer and the US attorney general to "look into" Joe Biden, who admitted publicly in 2016 of having threatened Ukraine authorities with withholding $1 billion in US loan guarantees if Kiev did not fire a prosecutor who was investigating a Ukrainian gas company linked to his son, Hunter.
The transcript did not, however, contain signs that the US president overtly threatened to withhold financial assistance to Ukraine if Zelensky did not do him this favor, but Democrats accuse Trump of using his power to request evidence against a potential competitor in the 2020 presidential race.