Mike Bloomberg has been angrily denounced as an arrogant and sexist billionaire – a wealthier version of Donald Trump – as Democrats turned on each other in their most contentious debate yet.

The former New York mayor, who has soared in the polls after spending up to $400m on political advertising, must have known he was going to come under fire in his first appearance in one of the party’s primary debates.

But the pumelling he received from his rivals in the first fifteen minutes on stage at Las Vegas’ Paris Theatre, felt like something more commonly seen in one of the boxing heavyweight prize fights frequently hosted at the nearby Caesar’s Palace.

Elizabeth Warren, conscious she was trailing Mr Bloomberg in the polls and needing to finally deliver a strong performance in Nevada’s caucus on Saturday, tore into him from the start.

“I’d like to talk about who we are running against. A billionaire who calls women fat broads and horse faced lesbians. And no I am not talking about Donald Trump. I am talking about mayor Bloomberg,” she said.

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“Look, I’ll support whoever the Democratic nominee is, but understand this, Democrats take a huge risk if we just substitute one arrogant billionaire for another.”

Mr Bloomberg, 78, was also attacked by Ms Warren over nondisclosure deals that a number of women who worked for him were asked to sign, after deals following complaints. Joe Biden, who was also looking for a chance to kickstart his fading campaign, was also happy to pile on, grateful for once not to be the target of his rivals’ attacks.

“We are not going to beat Donald Trump with a man who has who knows how many nondisclosure agreements and the drip, drip, drip of stories of women saying they have been harassed and discriminated against,” said Ms Warren.

Mr Bloomberg was also attacked for his policy of stop and frisk when he was New York mayor, something that was used invariably against people of colour. Mr Bloomberg has since apologised for the policy, and has said it was one of the things he was most embarrassed about from his time as mayor.

But his his fellow presidential hopefuls would not let it go.

“It’s not whether you apologise or not, it’s the policy. The policy was abhorrent,” said Mr Biden. “And it was in fact a violation of every right people have.”

Bloomberg makes disparaging remarks about transgender people

Even Mr Trump entered the fray. At a rally in Phoenix, Arizona, he said of Mr Bloomberg: “I hear he’s getting pounded tonight.”

Minnesota senator Amy Klobuchar, whose candidacy was kept alive by a strong third-place in New Hampshire after a solid performance at the last debate, also sought to land some punches.

Some were directed at Mr Bloomberg, but plenty were aimed at fellow Midwesterner and centrist Pete Buttigieg. When he criticised her for forgetting the name of the Mexican president at a forum, the evening before, she asked him if he was saying she was “dumb”.

“I said I made an error,” she added. “I think having a president that maybe is humble and is able to admit that here and there maybe wouldn’t be a bad thing.”

Much of the anger directed at Mr Bloomberg appeared to come from the fact he had soared in the polls, and onto the debate stage, while not contesting the first four voting states, and buoyed by vast personal wealth. He has said he is prepared to spend up to $2bn to defeat Mr Trump.

Asked about the apparent unfairness of someone “buying” their way onto the debate stage, Democratic Party chairman Tom Perez told reporters people had the chance to show their distaste by voting for someone else. “There are six candidates on the stage,” he said.

For his part, Mr Bloomberg did not crumple under pressure. Yet he also made no attempt to try and win over any new friends from his rivals.

In particular, he took aim at frontrunner Bernie Sanders, and his plan for universal healthcare.

“I can’t think of a way to make it easier for Donald Trump to get reelected than listening to this conversation,” he said at one point. “This is ridiculous. We’re not going to throw out capitalism. We tried that. Other countries tried that. It was called communism and it just didn’t work,” Mr Bloomberg said.

He said Mr Sanders had no chance of defeating Mr Trump, despite polls showing he performs as well as any of the candidates

“You don’t start out by saying I’ve got 160m people I’m going to take away the insurance plan that they love,” said Mr Bloomberg.