The Former Mayor of San Francisco Is Threatening to Sue Donald Trump. Here’s Why

Former San Francisco Mayor Willie Brown said he would consider suing former President Donald Trump in an interview with CBS News this week. His comments come amid a continued struggle over whether the two endured a treacherous helicopter ride together—something the former President and current Republican presidential nominee says did happen, but Brown says did not.

"Somebody has got to make sure that he stops lying," Brown is quoted as saying. “If he keeps it up, at some point, I'm going to give him a taste of his own conduct. If he sues the New York Times for printing that I said he lied, I'm going to sue him.”

During a press conference on Aug. 8 at his Mar-a-Lago estate in Florida, Trump was asked about Vice President Kamala Harris—the presumptive Democratic presidential nominee in the upcoming election—and her past relationship with Brown. (It’s understood that Harris and Brown dated for some time in the mid-1990s. In 2020, Brown authored an opinion piece for the San Francisco Chronicle titled: “Sure, I dated Kamala Harris. So what?”)

In response, Trump told a story, describing him and Brown as passengers of a helicopter that had an emergency landing.

“Well, I know Willie Brown very well,” Trump said. “In fact, I went down in a helicopter with him. We thought maybe this was the end. There was an emergency landing.”

Trump went on to say that Brown told him “terrible things” about Harris.

In his 2023 book Letters to Trump, in which he published his letters to a number of influential people—the former President discussed the alleged helicopter incident in the caption of a photo of him with Brown.

“We actually had an emergency landing in a helicopter together. It was a little scary for both of us, but thankfully we made it,” the caption read.

However, as reported by the New York Times soon after Trump’s press conference, Brown has denied this ever took place.

“You know me well enough to know that if I almost went down in a helicopter with anybody, you would have heard about it,” Brown, who also denied any ill-will between himself and Harris, told the publication. Current theories suggest that Trump may have mixed up Brown with other politicians. For example, former California Gov. Jerry Brown once rode with Trump in a helicopter in 2018 to survey wildfire damage, yet no emergency landing was reported. On Aug. 9, Politico also reported that former Los Angeles city councilman and state senator Nate Holden claimed he once rode with Trump in a helicopter heading to New Jersey, which a fellow passenger said ended in an emergency landing

After the New York Times posted the story on Aug. 8, Trump fought back the next day, reportedly calling Maggie Haberman, a reporter at the paper. According to Haberman, Trump shouted that he had proof of the alleged helicopter ride, and that he was  “probably going to sue” over the article.

Now, Brown has responded to Trump’s threat to sue.

In his interview with CBS News, Brown is also quoted as saying that Trump’s story is “a deliberate misrepresentation” and is just “a distraction from the magnificence” of Harris’ “ascendancy” in the past weeks since President Joe Biden endorsed her run for presidency, with most of the Democratic Party following suit.

TIME has reached out to the Trump campaign and the Willie Brown Institute for comment and further information.