In a move that is sure to ratchet up tension with the White House, cable news channel CNN is declining to run a new Trump 2020 presidential campaign ad, citing falsehoods and the ad’s open attacks on network stars.

The 30-second ad, titled “Biden Corruption,” peddles misleading accusations about Joe Biden and his son Hunter in an attempt by President Donald Trump to deflect from controversy over his pressuring of Ukrainian President Volodymyr Zelensky to dig up dirt on the former vice president.

“Joe Biden promised Ukraine $1 billion if they fired the prosecutor investigating his son’s company,” the cinematic trailer-like narrator blares. “But when President Trump asks Ukraine to investigate corruption, the Democrats want to impeach him,” the ad continues over footage of House Majority Leader Nancy Pelosi (D-CA).

“And their media lapdogs fall in line,” the narrator continues over footage of CNN stars Don Lemon, Chris Cuomo, and Jim Acosta, along with MSNBC primetime host Rachel Maddow.

“CNN is rejecting the ad, as it does not meet our advertising standards,” a network spokesperson told The Daily Beast. “Specifically, in addition to disparaging CNN and its journalists, the ad makes assertions that have been proven demonstrably false by various news outlets, including CNN.”

“CNN spends all day protecting Joe Biden in their programming, so it’s not surprising that they’re shielding him from truthful advertising too, and then talking to other media outlets about it,” Trump 2020 communications director Tim Murtaugh responded in a statement. “Our ad is entirely accurate and was reviewed by counsel, and CNN wouldn’t even describe to us what they found objectionable. This isn’t a cable news channel anymore, it’s a Democrat public relations firm.”

In reality, the Ukrainian prosecutor in question, Viktor Shokin, was viewed by multiple international bodies and the Obama administration as deeply ineffective in fighting corruption. The U.S. embassy in 2016 suggested $1 billion in loan guarantees as a way to push the Ukrainian government to enforce stricter anti-corruption policies, including the removal of officials like Shokin.

Biden publicly took credit for the idea—as seen in the clips the Trump campaign now weaponizes in the ad—but international organizations like the G7, International Monetary Fund (IMF), and the European Bank for Reconstruction and Development (EBRD) all reportedly wanted Shokin ousted.

This is not the first time CNN has rejected a Trump ad from airing during its broadcasts. Several months into the Trump presidency, in May 2017, the network refused to air a spot titled “100 Days,” which targeted alleged “fake news” networks, including CNN, for not properly giving the president credit for “making America great again.”

“CNN requested that the advertiser remove the false graphic that says the mainstream media is ‘fake news.’ The mainstream media is not fake news, and therefore the ad is false,” the network said at the time. “Per our policy, it will be accepted only if that graphic is deleted.”