Former Vice President Joe Biden Joe BidenFormer Pence aide: White House staffers discussed Trump refusing to leave office Progressive group buys domain name of Trump's No. 1 Supreme Court pick Bloomberg rolls out M ad buy to boost Biden in Florida MORE's presidential campaign called on news executives to stop booking Donald Trump Donald John TrumpFederal prosecutor speaks out, says Barr 'has brought shame' on Justice Dept. Former Pence aide: White House staffers discussed Trump refusing to leave office Progressive group buys domain name of Trump's No. 1 Supreme Court pick MORE's personal lawyer Rudy Giuliani Rudy GiulianiThe Hill's Campaign Report: GOP set to ask SCOTUS to limit mail-in voting CIA found Putin 'probably directing' campaign against Biden: report Democrats fear Russia interference could spoil bid to retake Senate 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.

ADVERTISEMENT

"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 Tapper Jacob (Jake) Paul TapperThe media's misleading use of COVID-19 data Julia Louis-Dreyfus: 'We can't spend much time grieving' Ginsburg Pence aide dismisses concerns rushed vote on Trump nominee will hurt vulnerable senators MORE, NBC's Chuck Todd Charles (Chuck) David ToddMurkowski: Supreme Court nominee should not be taken up before election Republican senator says plans to confirm justice before election 'completely consistent with the precedent' Sunday shows - Trump team defends coronavirus response MORE and Fox News's Chris Wallace Christopher (Chris) WallaceHouse to vote on resolution affirming peaceful transition of power Gayle King calls out Pelosi for calling Trump supporters 'henchmen': 'Egregious language' GOP lawmakers distance themselves from Trump comments on transfer of power 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.