Brian Stelter, host of CNN’s media affairs show Reliable Sources which was cancelled last week after 30 years on air, used his final episode Sunday to make a pointed rebuke of the network’s new bosses and their intention to pursue a more “neutral voice” to its coverage.

“It is not partisan to stand up for decency and democracy and dialogue,” Stelter said in his final monologue, which he stressed was unvetted by CNN management before he delivered it live. “It is not partisan to stand up to demagogues – it’s required, it’s patriotic.”

He added: “We must make sure we do not give a platform to those who are lying to our faces.”

CNN gave Stelter his marching orders last Wednesday, just four months after the network came under new leadership appointed by its owners, Warner Brothers Discovery. CNN head Chris Licht, who took over after the February departure of Jeff Zucker, has indicated that he wants to tone down the opinion quotient of its shows and “return” to an older, straighter and in his view less overtly leftwing style of reporting.

It is perhaps predictable that Stelter was to become one of the first casualties among CNN’s stars under the new leadership. As NPR’s media correspondent David Folkenflik explained, Stelter was a thorn in the side of the Donald Trump White House, regularly exposing its lies and misinformation.

As a result, he was “targeted for frequent criticism from conservatives for his coverage of the media during the Trump years”.

Since Stelter’s booting, New York’s medialand has been rife with speculation about its causation. Some have pointed the finger at John Malone, a powerful Discovery investor who has led the charge that CNN is too partisan.

Malone has criticized the network for broadcasting too much commentary and not enough on-the-ground reporting. Last November, Malone told CNBC that he would like to see CNN “evolve back to the kind of journalism that it started with, and actually have journalists, which would be unique and refreshing”.

Other speculation has focused on Stelter’s CNN salary – reported to be almost $1m a year – amid intense pressure to cut the network’s budget given heavy debts within the new media conglomerate.

So far the number of star scalps has been relatively small. A week before Stelter was axed, CNN’s chief legal analyst for 20 years, Jeffrey Toobin, announced that he was leaving.

Toobin had previously been suspended from the network for eight months after he exposed his genitals during a Zoom call with colleagues of his then-other media outlet, the New Yorker.

With Stelter’s departure, the focus at CNN is now likely to shift to whether further casualties of the new “neutral” reporting policy lie ahead. Speculation rippled through social media that Don Lemon and Jim Acosta, two of the more outspoken hosts, might be vulnerable, but according to the entertainment news website The Wrap they are safe for now.

Part of Stelter’s argument as host of Reliable Sources, CNN’s longest-running show until its demise, was that it is the role of the media to hold power to account. That function was especially critical in the febrile age of Trump.

With Trump hinting at another presidential run in 2024, Stelter appealed on Sunday to the bosses who had just fired him to remain resolute. “The watchword here is accountability,” he said. “CNN needs to be strong. I believe America needs CNN to be strong.”

In his at times emotional last address on Reliable Sources, the largely bald-headed Stelter recalled his astonishment at becoming a TV star. “I never thought I’d actually be on TV – I just liked writing about TV,” he said. “I know this is going to sound like BS, but I thought I didn’t have enough hair to be on TV.”