In late May, the massively influential radio network Westwood One debuted a new daily talk show from Dan Bongino, a former Secret Service agent and New York City cop who gained stature in conservative media during the presidency of Donald Trump. The show occupies the noon-3 p.m. time slot once dominated by Rush Limbaugh, setting Bongino up as one of the key challengers for his audience.

Within two months, the show had reached distribution on more than 300 stations, which the company described as “impressive growth.”

Now, Bongino is threatening to walk away completely. He has taken issue with a vaccination mandate imposed in August by Westwood One’s owner, Cumulus Media. Chief executive Mary Berner gave all employees until Sept. 27 to be fully vaccinated against the coronavirus before an expected return to the office and wrote that “it would neither be fair nor do we have the bandwidth to make exceptions based on individual preferences,” according to industry publication Inside Radio.

Several Cumulus radio hosts have already quit or been terminated because of a stated preference not to be vaccinated for personal or medical reasons, and Bongino is threatening to join them. Though the host’s team says that he has been vaccinated on the advice of his doctors because he has Hodgkin’s lymphoma, Bongino is objecting to a mandate on behalf of rank-and-file employees who don’t want to get vaccinated.

“I’m not really happy with the company I work with right here,” Bongino told listeners on Monday. “I believe these vaccine mandates are unethical. I believe they’re immoral. I believe they don’t take into account the science of natural immunity due to a prior infection. I believe they’re broad-based and don’t take into account an individual circumstances of why they may or may not want to take a vaccine. And they’re antithetical to everything I believe in.”

“So, I’ll say again, I’m not going to let this go,” Bongino added. “Cumulus is going to have to make a decision with me — if they want to continue this partnership or they don’t. But I’m talking to you on their airwaves. They don’t have to let that happen. And I wouldn’t mind if they didn’t. Because it’s really unfortunate that people with a lower profile than me, who don’t have 300-plus stations, have been summarily either shown the door or been put in really untenable circumstances because they simply want to make a medical decision by themselves.”

If Cumulus Media does not relax the vaccination mandate, “this is going to be an entirely untenable situation going forward,” said Bongino, who promised to revisit the subject every day until it is addressed.

If he leaves the network, Bongino would be the most prominent conservative media personality to quit a job over a vaccination mandate. Cumulus has not replied to emails from The Washington Post seeking comment.

Bongino’s radio show is also simulcast on the Fox News streaming service Fox Nation, and he hosts a Saturday-night show on the network titled “Unfiltered.” Although Fox News’s parent company Fox Corp has not introduced a vaccination mandate, a human resources memo sent last month said a “small group of employees” who are not vaccinated or chose not to share their vaccination status are required to be tested on a daily basis. More than 90 percent of rank-and-file Fox employees have reported that they are fully vaccinated, according to the memo.

Fox News personalities who oppose vaccine mandates and have inveighed against them on air have largely refrained from calling out the company’s vaccination policies, and Bongino didn’t critique Fox as he chewed out Cumulus during his radio show on Monday.

Last week, Fox News host Tucker Carlson was asked about Fox’s policies on a podcast from the Daily Caller, the conservative-leaning news site he co-founded.

“I’m not qualified to speak for the company on this,” Carlson said, “because I don’t run the company. I’m just an employee of the company. My personal preference is that Fox News would make a statement about what their policies are, but I think, like a lot of companies, they’re hesitant to do that, because, like, why would you even want to get involved in that conversation?”

Bongino’s broadside against Cumulus Media is not the first time he has publicly challenged one of the media conglomerates he works with. In August, Bongino called out Fox News after the YouTube version of an interview he conducted with Trump excluded a reference to a “fake election," though the edit remains in the version online.