Elizabeth Warren's campaign is buying ads on Facebook which falsely claim that CEO Mark Zuckerberg has endorsed President Trump - before quickly admitting it's not true.

The message? Facebook needs to fact-check ads by politicians.

The Democratic presidential candidate’s campaign sponsored the posts that were blasted into the feeds of U.S. users of the social network, pushing back against Facebook’s policy to exempt politicians’ ads from its third-party fact-checking program. The ad begins with a lie: Facebook’s chief executive officer “just endorsed” Trump for re-election. It quickly backtracks to the truth. -Bloomberg

"You’re probably shocked. And you might be thinking, ‘how could this possibly be true?" the ad says. "Well, it’s not."

"What Zuckerberg ‘has’ done is given Donald Trump free rein to lie on his platform -- and then to pay Facebook gobs of money to push out their lies to American voters," reads Warren's ad.

Hilariously, Bloomberg's example of an 'untrue' Trump ad revolves around video evidence of former Vice President Joe Biden threatening to withhold $1 billion in US loan guarantees from Ukraine if they didn't fire a prosecutor investigating a gas company paying his son $600,000 per year.

The Biden campaign has asked both Twitter and Facebook to remove the Trump ads, however both platforms have refused according to The Verge. "The ad you cited is not currently in violation of our policies," said one Twitter spokesman.

Facebook’s decision to allow Trump’s ad contrasts with CNN, which rejected a request by the president’s campaign to run what the network called two “demonstrably false” claims. “If Senator Warren wants to say things she knows to be untrue, we believe Facebook should not be in the position of censoring that speech,” Andy Stone, a spokesman for Facebook, said in a statement to CNN on the ads. -Bloomberg

Warren, meanwhile, is also guilty of false advertising - such as an Instagram video which suggests she might be fun to share a beer with.