Former Vice President Joe Biden's presidential campaign on Sunday sent a letter to television executives at ABC, CBS, CNN, Fox News and NBC, demanding they no longer book Rudy Giuliani on their network. Political anchors Jake Tapper, Chuck Todd and Chris Wallace were also included on the emails. The letter was written by campaign advisers Anita Dunn and Kate Bedingfield, the New York Times reported.

Giuliani has made the rounds on cable TV, defending President Donald Trump after a full unclassified and unredacted transcript of Trump's call with Ukrainian President Volodymyr Zelensky was released.

During the call, Trump told Zelensky to work with Giuliani and Attorney General William Barr on investigating Hunter Biden's involvement with a Ukrainian oil company while his father, then-Vice President Joe Biden, had dealings with the country.

Here's a copy of the letter:

September 29, 2019

All --

We are writing today with grave concern that you continue to book Rudy Giuliani on your air to spread false, debunked conspiracy theories on behalf of Donald Trump. While you often fact check his statements in real time during your discussions, that is no longer enough. By giving him your air time, you are allowing him to introduce increasingly unhinged, unfounded and desperate lies into the national conversation.

We write to demand that in service to the facts, you no longer book Rudy Giuliani, a surrogate for Donald Trump who has demonstrated that he will knowingly and willingly lie in order to advance his own narrative.

Just today, for example, he tried to resurrect the argument that Vice President Biden's anti-corruption work in Ukraine was intended to benefit his son, when every single independent outlet has reported that the Vice President Biden was advancing the foreign policy goals of the United States government, the European Union, the International Monetary Fund, the World Bank and more by pushing to oust a prosecutor who was known to be in contempt.

He also tried to raise completely baseless suggestions about Hunter Biden's work in China that have been pushed by conservative mouthpiece Peter Schweitzer and have been roundly debunked as false in mainstream outlets. He spouted this while pointedly avoiding answering directly a question about whether he had spoken to Chinese authorities directly in an attempt to manufacture this smear – just as he did with the Ukrainians.

Rudy Giuliani has made clear time and again that he will lie on television – often contradicting himself multiple times over the course of one answer. This morning on CBS, he attacked the credibility of the former Ukrainian prosecutor on whom he has previously staked most of his harebrained case against Biden when the prosecutor said definitively he believed there was nothing here to investigate. Giuliani is not enlightening your viewers in any way. He's not offering a unique or informed perspective. He's certainly not introducing new facts, since his relationship with the truth is casual at best.

Giuliani is not a public official, and holds no public office that would entitle him to opine on the nation's airwaves. The decision to legitimize his increasingly outlandish and unhinged charges and behavior – calling it "news" – rests solely with you. And let us be clear: we do not believe you should be giving legitimacy to someone who has publicly said he is concerned his tombstone will he say he "lied for Donald Trump," – but if you do, you need to give an equivalent amount of time to a surrogate from the Biden campaign. Vice President Biden and his campaign are the target of these attacks. 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.

Your obligation is to provide the American people with an informed, fact-based and responsible coverage and debate of critical issues. Rudy Giuliani has made very clear that his only obligation to protect Donald Trump, and that he will willingly lie to do so. While you have been aggressive in pushing back on him in real time, it is well-known that the dedicated liar always has the advantage, pushing out outland falsehoods and disinformation in the knowledge that 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.

We ask that you no longer book him on your air.

Sincerely,

Anita Dunn and Kate Bedingfield

Biden for President