WASHINGTON (Reuters) - Lawyers for U.S. President Donald Trump and his re-election campaign have threatened in a letter to sue CNN for what they said was the network falsely advertising itself as a news organization, calling on executives to first discuss an “appropriate resolution” to the matter that would include a “substantial” payment to cover damages.

FILE PHOTO: U.S. President Donald Trump holds a congratulatory phone call for the first all-female space walk outside of the International Space Station with astronauts Christina Koch and Jessica Meir at the White House in Washington, D.C., U.S. October 18, 2019. REUTERS/Leah Millis

The letter, dated Oct. 16 and made public on Friday, is the latest threat by Trump to sue a media organization over what he sees as unfair media coverage since launching his 2016 presidential campaign, although no lawsuits have been filed.

“This is nothing more than a desperate PR stunt and doesn’t merit a response,” a CNN spokesman said in an email.

Rebecca Tushnet, a professor of false advertising law at Harvard Law School, said there was “no merit” to the letter’s legal arguments and that she doubted a lawsuit would ever be filed.

The letter was signed by Charles Harder, who has sent similar threats to media organizations on Trump’s behalf.

Last year, Harder suggested Trump would take legal action against the New York Times for an investigative report on his business empire, calling it “highly defamatory.”

Harder also threatened a libel lawsuit over “Fire and Fury: Inside the Trump White House” by author Michael Wolff, a book that portrayed an inept president in a fumbling White House.

Trump has frequently lashed out at CNN and other news organizations, calling them “fake news” and “the enemy of the people.”

On Nov. 7, 2018, the day after congressional elections, Trump erupted into anger during a news conference when CNN’s White House correspondent Jim Acosta questioned him about the probe of Russian interference in the 2016 election and a migrant caravan traveling through Mexico.

The White House suspended Acosta’s credentials later that day, alleging Acosta had put his hands on an intern who was trying to take a microphone from him. Videos of the encounter show Acosta pulling back as the intern moved to take the microphone.

The White House later restored Acosta’s press access, ending a lawsuit brought by CNN challenging the revocation as a violation of the reporter’s constitutional rights. A judge had issued a temporary ruling in CNN’s favor.