Before a crowd at the business school at Oxford University, Bloomberg relayed a lighthearted story about speaking with Trump after a Sept. 11, 2001 memorial service apparently in 2016. "I saw your speech in Philadelphia," Trump told Bloomberg, a seeming reference to Bloomberg's takedown of Trump at the Democratic National Convention that summer.

"But you really do love me, don't ya?" Trump continued, in Bloomberg's retelling. "And I said, 'Yes, Donald, I do love you, I just disagree with everything you've ever said.'"

"And we had a good laugh," Bloomberg continued. "If you’ve sat and had dinner with Donald Trump, you’d probably walk away saying everything he just said is bullshit, he can’t be doing that. But you have a good time. He is socially a nice person. Will he be a good president? I hope so. Because we desperately need leadership in the country and the world.”

The intensified scrutiny of Bloomberg’s history with Trump comes as the White House hopeful is spending record sums disparaging Trump in TV and radio ads.

On Tuesday, in a statement to POLITICO, the Bloomberg campaign downplayed the former New York City mayor's past praise of the president.

“When Mike was mayor, he hired Donald Trump to run a city golf course, and that's the only job he’s hired him for,” said Stu Loeser, a senior adviser to the campaign and longtime spokesman for Bloomberg as mayor. “When Trump was headed to the White House, like most Americans Mike Bloomberg hoped Donald Trump would rise to the occasion. Instead, Trump’s lowered expectations for leadership and failed Americans on issue after issue. That’s why Mike is running to replace him, and Mike’s record and resources are why more and more Americans are supporting Mike.”

Asked whether Bloomberg, who once also talked about he and Trump being on a first-name basis, now regretted making flattering comments about Trump, Loeser said, “Mike isn't big on shouldas, couldas or wouldas. His mind works looking forward, and with more and more Americans saying that Mike is the only one who can kick Donald Trump out of office, the thing Mike Bloomberg is looking forward to most is using his record and resources to help save America.”

This week Bloomberg’s dealings with Trump came to a head in the Democratic primary after his and Sanders’ campaign traded accusations that one was closer to the president than the other. On the trail, Sanders has opened up a line of attack against the billionaire, accusing him of trying to buy the election.

Bloomberg campaign manager Kevin Sheekey posted a statement on Monday with the subject line, “Bernie’s new bro: Donald Trump.” Sheekey went on to describe Sanders' attacks on Bloomberg as “shameful,” accusing him of replicating Trump campaign tactics. “At this point, the primary is Bernie’s to lose and ours to win. Bernie knows this. Trump knows this. That’s why they are united in the campaign against Mike.”

Sanders’ response? Posting a photo, without comment, of a grinning Bloomberg with Trump on a golf course together.

“Billionaires often have more in common with each other than they do with the working class, and the people know that,” said Mike Casca, a Sanders campaign spokesman said in a statement to POLITICO.

But, perhaps in a sign of what will come Wednesday night on the debate stage, Bloomberg’s camp took it a step further.

“Mike made a lot of money but never forgot he came from a middle class home, whereas Bernie foamed about millionaires several times a day until recently when somebody reminded him that he’s a millionaire, too,” Loeser said, pointing to this link.

For its part, Trump’s campaign characterized Bloomberg’s past and present statements as two-faced.

“Envy and ambition overpower everything else for Mike Bloomberg,” said Trump campaign spokesman Tim Murtaugh. “He’s just like Hillary Clinton and many others — happy to be friendly with Donald Trump when it’s convenient, but eager to attack him when it’s politically expedient.”