Marc Benioff, the Salesforce CEO and co-founder, is facing growing criticism over a joke he made about US Immigration and Customs Enforcement (ICE) monitoring international employees during an event for the company.

Employees publicly expressed outrage about Benioff’s comments in his keynote address at an internal conference in Las Vegas on Tuesday, and leaders at Slack, which Salesforce owns, have said he should apologize.

Benioff reportedly asked international employees to stand, before joking that ICE agents were present and monitoring them, drawing boos from the crowd, several employees told media outlets including Wired and 404Media. A recording of his speech published on an internal Salesforce site was edited to cut his remarks about ICE, Business Insider reported.

The incident comes as hundreds of Salesforce workers reportedly plan to urge Benioff to denounce ICE and cancel future business with the agency, Wired and CNBC reported.

Much like other billionaires, Benioff’s politics appear to have taken a marked turn in Trump’s second term. He for years was closely aligned with some liberal causes, including a 2018 measure in San Francisco to tax large corporations in the city to fund homeless services, and in an interview with the Guardian criticized billionaires for “hoarding” their wealth.

Last fall Benioff told the New York Times he “fully supported” the president, and said Trump should send national guard troops to San Francisco, before apologizing and walking those comments back. His company, which has long had contracts with ICE, has sought to increase its business with the agency.

Now he faces outrage within his company and others with ties to Salesforce over his recent jokes about international employees, ICE and a remark about not understanding Bad Bunny’s recent Super Bowl performance. Employees have condemned his comments on Slack and LinkedIn.

Farone Rasheed, a Salesforce employee, wrote on the networking site: “I am fearful for my friends and co-workers on my team who are here on international visas … I am shocked, angered, sad and frustrated by the views espoused by the leadership at Salesforce this week. I’m sharing this here because, frankly, I fear retaliation for that.”

Rob Seaman, Slack’s general manager, was critical of Benioff’s comments in an internal company message, according to Business Insider.

“I want to acknowledge the jokes that happened this morning at CKO,” Seaman wrote, the outlet reported. “I cannot defend or explain them. They do not align with my personal values and I know this to be the case for many of you as well.”

Salesforce did not immediately respond to a request for comment.