Former Vice President Joe BidenJoe BidenAmash calls McCarthy incompetent, dishonest after '60 Minutes' interview GOP lawmaker blasts Trump for quoting pastor warning of civil war over impeachment '60 Minutes' correspondent presses McCarthy on impeachment inquiry MORE's presidential campaign called on news executives to stop booking Donald TrumpDonald John TrumpAmash calls McCarthy incompetent, dishonest after '60 Minutes' interview GOP lawmaker blasts Trump for quoting pastor warning of civil war over impeachment '60 Minutes' correspondent presses McCarthy on impeachment inquiry MORE's personal lawyer Rudy GiulianiRudy GiulianiSchiff says he plans to subpoena Giuliani for documents Biden campaign demands news channels stop booking Giuliani Trump allies go on the offensive against whistleblower complaint, Democrats MORE as a guest on news programs.

Two top Biden campaign advisers in a letter addressed the leaders of news and cable networks and some anchors, saying that Giuliani's appearances on news networks are giving the lawyer and his "false, debunked conspiracy theories" undeserved credibility, The Daily Beast first reported. The letter has since been shared on social media.

"While you often fact check his statements in real time during your discussions, that is no longer enough," the letter says. "By giving him your air time, you are allowing him to introduce increasingly unhinged, unfounded and desperate lies into the national conversation."

The Biden advisers — Anita Dunn and Kate Bedingfield — argue that "Giuliani is not a public official, and holds no public office that would entitle him to opine on the nation’s airwaves."

"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 outlandish falsehoods and disinformation in the knowledge that it is hard for the corrections to catch up," the letter reads, according to The Daily Beast. 

The Hill has reached out to the Biden campaign for comment. 

The president's lawyer responded to The Daily Beast in a text saying the letter "sounds like the usual left wing censorship."

"Everything I say is supported by such as today, affidavits and statements," Giuliani said. "They are the ones who have covered up pay for play for at least 5 years."

Recipients of the letter included NBC President Noah Oppenheim, CBS News President Susan Zirinsky, CNN President Jeff Zucker, CNN's Jake TapperJacob (Jake) Paul TapperBiden campaign demands news channels stop booking Giuliani Trump allies go on the offensive against whistleblower complaint, Democrats Tapper fact-checks GOP rep in real time MORE, NBC's Chuck ToddCharles (Chuck) David ToddBiden campaign demands news channels stop booking Giuliani Scalise defends Trump Ukraine call: 'I'm glad President Trump continues to look into [Russian] interference' Chuck Todd, John Kennedy get in heated exchange over Trump-Ukraine controversy: 'Don't gaslight us' MORE and Fox News's Chris WallaceChristopher (Chris) WallaceBiden campaign demands news channels stop booking Giuliani Trump allies go on the offensive against whistleblower complaint, Democrats Sunday shows — Impeachment grips Washington MORE, according to The Daily Beast.

Giuliani appeared on ABC's "This Week" and CBS's "Face the Nation" on Sunday morning, centering most of his interviews on accusing Biden and his son of corrupt involvement in the Ukraine. 

"I am defending my client the best way I know how," Giuliani said on "This Week." "This is not about getting Joe Biden in trouble. This is about proving that Donald Trump was framed by the Democrats." 

As of now, there is no evidence to support Giuliani's assertions that Biden or his son participated in corruption in the Ukraine.