Rick Wilking / Reuters The knighted British billionaire had previously said he didn't want Trump to be president.

Richard Branson skewered Donald Trump on Friday, describing a “bizarre” meeting at some point in the past that left the British billionaire “disturbed and saddened.”

In a blog post on his website, the Virgin founder said the Republican nominee invited him over “some years ago” for a one-on-one lunch at his gilded Manhattan apartment. Soon after sitting down to the meal, Branson said, Trump launched into a vicious tirade, vowing vengeance on people who’d refused to lend him money during one of his six bankruptcies.

“Even before the starters arrived he began telling me about how he had asked a number of people for help after his latest bankruptcy and how five of them were unwilling to help,” Branson, 66, wrote. “He told me he was going to spend the rest of his life destroying these five people.”

Branson said Trump “didn’t speak about anything else.”

“I was baffled why he had invited me to lunch solely to tell me this,” Branson wrote. “For a moment, I even wondered if he was going to ask me for financial help. If he had, I would have become the sixth person on his list!”

Valued at about $5 billion, Branson is now one of several people in the so-called “three comma club” to criticize Trump.

Warren Buffett, the world’s third richest person with $64.5 billion, admonished Trump earlier this month for refusing to release his tax returns. Dallas Mavericks owner Mark Cuban, worth about $3.3 billion, has repeatedly antagonized Trump on Twitter and in the press. Former New York City Mayor Michael Bloomberg, whose wealth Forbes puts at about $43.6 billion, has called him “risky and reckless” and questioned the former reality TV star’s net worth.

Trump’s actual net worth is unclear. The real estate mogul claims to be worth $10 billion, but Forbes pegs his wealth at $3.7 billion. Bloomberg’s Billionaire Index valued him at $3 billion, and Tim O’Brien, a former Huffington Post editor and author of a book about Trump, claimed last year that the mogul could be worth as little as $150 million.

Even Charles and David Koch, the billionaire conservative megadonors, have refused to back Trump for president. Charles, worth $42.1 billion, compared Trump’s proposed policies on Muslims to those of a Nazi. David, valued at $17.5 billion, pulled his support for the Republican National Convention in July after it was clear Trump would be the party’s nominee.

“What concerns me most, based upon my personal experiences with Donald Trump, is his vindictive streak, which could be so dangerous if he got into the White House,” wrote Branson, who, as a British citizen, cannot vote in the U.S. election. “For somebody who is running to be the leader of the free world to be so wrapped up in himself, rather than concerned with global issues, is very worrying.”

By contrast, Branson said, the conversation at the first one-on-one lunch he shared with Democratic nominee Hillary Clinton revolved around education reform, the war on drugs, women’s rights, conflicts around the world and the death penalty.

“She was a good listener as well as an eloquent speaker,” he wrote. “As she understands well, the President of the United States needs to understand and be engaged with wider world issues, rather than be consumed by petty personal quarrels.”

Editor’s note: Donald Trump regularly incites political violence and is a serial liar, rampant xenophobe, racist, misogynist and birther who has repeatedly pledged to ban all Muslims — 1.6 billion members of an entire religion — from entering the U.S.