Musk will attend a conference next week in Miami, where he will meet privately with advertisers and marketing executives and speak about what the new version of Twitter means for marketers. But in a leaked email exchange first reported by Semafor Thursday, some of the country’s biggest advertisers remain concerned about being associated with Musk, accusing him of contributing to the spread of hate speech on Twitter. 

“While I am a huge supporter of free speech and enterprise we can not ignore the impact of such hate speech. I especially can’t ignore it as a black woman,” Diana Haussling, vice president at Colgate-Palmolive, is quoted as writing in the email. She added that she would be “mindful of the harmful and often racist rhetoric of Elon Musk.”

Since Musk took ownership of Twitter, critics say, his advocacy for free speech and growing disdain for left-wing “wokeness” has empowered far-right viewpoints on the platform. Musk has said multiple times on Twitter that he is committed to reducing the rate of hate speech. “Negative/hate tweets will be max deboosted & demonetized, so no ads or other revenue to Twitter,” he wrote in a November tweet. And in December, Musk reported that hate speech impressions—the number of times a hateful tweet appears in timelines or search results—had fallen by a third since he took over the company.

But even if hate speech impressions fell, the total number of hateful tweets soared in the weeks after Musk bought Twitter. The number of daily tweets containing racial slurs against Black people surged over 200% after the takeover, according to a December report from the Center for Countering Digital Hate, the Anti-Defamation League, and other groups. The volume of anti-Semitic posts also increased by 61%, while tweets containing slurs against gay men soared 58%.

The rise of hateful rhetoric, and the gutting of content moderation teams at Twitter who could clamp down on it, has increased the presence of extremist views, J.M. Berger, a writer and researcher focused on extremism in the U.S. and on social media, argued in an interview with Insider in January. Companies say the platform has become a more difficult environment to stay visible in, and in the month after Musk purchased Twitter, half of the company’s top 100 advertisers halted spending on the platform.

“For many communities, his willingness to leverage success and personal financial resources to further an agenda under the guise of freedom of speech is perpetuating racism resulting [in] direct threats to their communities and a potential for brand safety compromise we should all be concerned about,” Tariq Hassan, chief marketing and customer experience officer at McDonald’s, wrote in the email exchange leaked to Semafor.

“[A]ll of us who lead our brand’s investments across platforms were required to navigate a situation post-acquisition that objectively can only be characterized as ranging from chaos to moments of irresponsibility,” he added. 

In addition to flagging the rise of hateful rhetoric on Twitter, company executives in the exchange voiced their concerns over Musk’s own conduct in recent months.

“By giving Elon Musk a stage, we have signed up to broker an important discussion that must be managed with the utmost of care and respect for those most harmed by his actions and inactions,” Kristi Argyilan, senior vice president of retail media at grocery chain Albertsons, wrote in the exchange.

The emails did not reference a specific incident, but Musk came under fire in February for accusing the media and schools of being “racist” against white and Asian people while standing up for cartoonist Scott Adams, creator of the Dilbert comic strip. Adams had recently made racist comments in a video posted to his YouTube channel, calling Black Americans a “hate group.”

Chris Riedy, Twitter’s vice president of global sales and marketing, was also present on the thread. He called the executives’ feedback “critical” and offered to set up private meetings with Musk next week.

Musk has tried to move Twitter past its ad-reliant business model since becoming CEO, but his paid subscription alternative has so far underwhelmed users, with several celebrities and media organizations already announcing their intention to leave the platform. In 2021, advertising was responsible for 90% of Twitter’s revenue, and in a February tweet, Musk suggested that the company was close to bankruptcy when he purchased it.

Colgate-Palmolive, McDonald’s, and Albertson’s did not immediately respond to Fortune’s request for comment. Twitter has not had an active press office since November and no longer replies to media inquiries.