Elizabeth Warren should expect a huge legal battle if she becomes the next US president and tries to lead a breakup of Facebook.

Facebook CEO Mark Zuckerberg threatened “to go to the mat” and “fight” in an internal employee meeting in July, according to transcripts and audio recordings of the comments that the Verge published on Tuesday.

Asked by an employee about Warren and a potential breakup, Zuckerberg said, “I’m certainly ... worried that someone is going to try to break up our company.”

“So there might be a political movement where people are angry at the tech companies or are worried about concentration or worried about different issues and worried that they’re not being handled well,” he added. “That doesn’t mean that, even if there’s anger and that you have someone like Elizabeth Warren who thinks that the right answer is to break up the companies. ... I mean, if she gets elected president, then I would bet that we will have a legal challenge, and I would bet that we will win the legal challenge. And does that still suck for us? Yeah. I mean, I don’t want to have a major lawsuit against our own government.”

But Zuckerberg told employees, “if someone’s going to try to threaten something that existential, you go to the mat and you fight.”

On Tuesday, Warren tweeted in response: “What would really ‘suck’ is if we don’t fix a corrupt system that lets giant companies like Facebook engage in illegal anticompetitive practices, stomp on consumer privacy rights, and repeatedly fumble their responsibility to protect our democracy.”

What would really “suck” is if we don’t fix a corrupt system that lets giant companies like Facebook engage in illegal anticompetitive practices, stomp on consumer privacy rights, and repeatedly fumble their responsibility to protect our democracy. https://t.co/rI0v55KKAi — Elizabeth Warren (@ewarren) October 1, 2019

In March, Senator Warren outlined a plan to break up several tech giants, including Facebook, that she argued have “stifled innovation.”

In Facebook’s case, she said she would appoint regulators who would “unwind anti-competitive mergers” like the social network’s acquisitions of Instagram and WhatsApp as part of an effort to “promote healthy competition in the market which will put pressure on big tech companies to be more responsive to user concerns, including about privacy.”

Other Democratic presidential candidates, such as Senators Bernie Sanders and Amy Klobuchar, have also said they would consider breaking up the tech giants.

“I think that the direction of the discussion is concerning,” Zuckerberg told employees in July. “I don’t think that the antitrust remedies are going to solve them. But I understand that if we don’t help address those issues and help put in place a regulatory framework where people feel like there’s real accountability, and the government can govern our sector, then yeah, people are just going to keep on getting angrier and angrier. And they’re going to demand more extreme measures, and, eventually, people just say, “Screw it, take a hammer to the whole thing.” And that’s when the rule of law comes in, and I’m very grateful that we have it.”

Zuckerberg’s leaked comments to employees were made in the same month that Facebook reached a $5 billion settlement with the Federal Trade Commission over privacy failures related to the Cambridge Analytica scandal. Critics argued that the deal was essentially a slap on a wrist for a company that generates $16 billion of revenue alone in a three-month period.

The Facebook staff meetings also happened in the midst of an escalating national discussion over the power and dominance of the giant tech companies and increased anti-trust scrutiny from regulators.

In the discussions with employees, Zuckerberg also made a case that if Facebook were broken up, it would have fewer resources to detect hate speech and election interference efforts.

“It’s just that breaking up these companies, whether it’s Facebook or Google or Amazon, is not actually going to solve the issues,” Zuckerberg said “And, you know, it doesn’t make election interference less likely. It makes it more likely because now the companies can’t coordinate and work together. It doesn’t make any of the hate speech or issues like that less likely. It makes it more likely because now ... all the processes that we’re putting in place and investing in, now we’re more fragmented.”

It’s an argument Facebook has made before — the bigger we are, the more equipped we are to fight the bad actors — but it’s also one that’s come under scrutiny by legislators.

Using Twitter as an example of the limitations of being a relatively smaller company, Zuckerberg said the company “can’t do as good of a job” as Facebook.

“I mean, they [Twitter] face, qualitatively, the same types of issues. But they can’t put in the investment. Our investment on safety is bigger than the whole revenue of their company. [laughter] And yeah, we’re operating on a bigger scale, but it’s not like they face qualitatively different questions. They have all the same types of issues that we do.”