Former Vice President Joe Biden's 2020 campaign demanded in a letter first reported by The Daily Beast that television networks stop booking Rudy Giuliani, arguing that he will "knowingly and willingly lie in order to advance his own narrative."

The big picture: Giuliani, President Trump's personal attorney and a frequent guest on cable news, has adamantly defended his and Trump's efforts to push Ukrainian officials to investigate Biden and his son over unsubstantiated corruption allegations. Several of Giuliani's recent appearances have gone viral due to their combative nature — most notably one with CNN's Chris Cuomo last weekend in which Giuliani was forced to walk back his claims that he never asked Ukraine to investigate Biden in the first place.

The letter from top Biden officials Anita Dunn and Kate Bedingfield argues that while journalists "have been aggressive in pushing back on [Giuliani] in real time ... it is hard for the corrections to catch up."

"Giving Rudy Giuliani valuable time on your air to push these lies in the first place is a disservice to your audience and a disservice to journalism," the letter reads.

The campaign also adds that should networks continue to book Giuliani, they need to be giving "an equivalent amount of time" to a Biden surrogate.

"Saying simply that you will put a Democrat on, at a time when there are many declared candidates for the Democratic nomination for the presidency, is neither fair treatment nor equal treatment."

Read the letter:

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