Mark Zuckerberg has left D.C., but politicians want more from him.

Sen. Mark Warner wants sent a letter to the Facebook CEO late Monday asking him to reconsider his company's policy that allows politicians and elected officials to run false and misleading paid advertisements on the platform.

"While Facebook's advertising rules have long prohibited ads with 'deceptive, false, or misleading content' — relying on its 'third-party fact-checkers' to identify violations of these policies — Facebook subsequently revised these rules to exempt political ads run by politicians through a policy that withholds such ads from third-party fact-checker review," Warner wrote in the letter.

The Virginia Democrat went on to criticize Facebook's protection by the Communications Act, which Warner said prohibits national broadcasters from rejecting or modifying qualified federal candidates' ads, regardless of their accuracy. The senator argued that Facebook should hold itself to the same standard as broadcasters, specifically citing CNN.

"In making strides not to continue contributing to the coarsening of our political debate, and the undermining of our public institutions, at a minimum, Facebook should at least adhere to the same norms of other traditional media companies when it comes to political advertising," Warner's letter says. "Therefore, the industry norms Facebook should heed would more aptly be those followed by not by local broadcasters, but by cable networks."

A Facebook spokesperson confirmed that the company received the letter, and directed CNBC to links of Zuckerberg's interview with NBC News' Lester Holt last week and to his speech on free expression at Georgetown University earlier this month.

Facebook's policy to allow politicians and elected officials to promote false and misleading ads came under scrutiny earlier this month after the Trump 2020 campaign promoted a series of ads containing false information about his political opponent, former Vice President Joe Biden. The topic was much discussed earlier this month when Zuckerberg appeared before Congress to testify on Facebook's plans to launch the libra cryptocurrency.

Warner is among the members of Congress most active in the movement to regulate Big Tech companies. He has written and introduced a number of bills on the subject including the Honest Ads Act, which is meant to prevent foreign interference in future elections and improve the transparency of online political advertisements.

Read Warner's full letter here: