Longtime CNN host Don Lemon has been sacked by the U.S.-based cable television network, while on the other side of the political spectrum, conservative firebrand, Tucker Carlson left Fox News in a shock move.

Lemon said in a Twitter post on Monday that he was "stunned" by the step and that he was not directly informed of the termination by the network.

"I was informed this morning by my agent that I have been terminated by CNN. I am stunned," he said.

"After 17 years at CNN, I would have thought that someone in management would have had the decency to tell me directly. At no time was I ever given any indication that I would not be able to continue to do the work I have loved at the network," he added.

In a statement of its own, CNN said the network and Lemon had parted ways. It added that Lemon was offered a chance to meet with the network's management but that he instead released a statement on his personal Twitter account. The network described Lemon's version of events as "inaccurate."

Neither statement gave a reason for Lemon's departure.

Lemon joined CNN in 2006. He hosted the prime-time show "Don Lemon Tonight" for more than eight years and gained prominence during the presidency of Donald Trump for his commentary on the former Republican president, whom he called a "racist."

Trump welcomed Lemon's departure from CNN. On his Truth Social platform, the former president said: "My only question is, WHAT TOOK THEM SO LONG?"

Lemon faced severe criticism earlier this year for comments made on air during a discussion about Republican presidential candidate Nikki Haley's proposal that people over the age of 75 who wish to serve in the White House should prove mental competence.

He said Haley was not in her prime and that a woman's prime is in her 20s, 30s, or "maybe her 40s." He later apologized for the sexist comments.

In response to Lemon's departure from CNN, Haley tweeted Monday: "A great day for women everywhere."

Fox, Carlson part ways

In a separate development, conservative commentator Tucker Carlson, the host of Fox News' most popular show, announced he was leaving the network, just days after the outlet paid a huge settlement to end a defamation case.

Carlson was the best-known personality on Fox's presenting roster, hosting a prime-time evening show that resonated with the broadcaster's substantial number of right-wing viewers.

A key figure in Republican politics, he often interviewed Donald Trump and has been widely criticized for his alleged lack of journalistic rigor and – to his critics – his stream of disinformation and racist and hate-filled rhetoric.

"Fox News Media and Tucker Carlson have agreed to part ways. We thank him for his service to the network as a host and prior to that as a contributor," the network said in a statement, giving no reason for his departure.

The 53-year-old Carlson, who joined Fox in 2009, provided no immediate reaction.

Railing against everything from immigration policies to gun controls, "Tucker Carlson Tonight" pilloried liberal trends in modern America, appealing to viewers' outrage and propelling the show to the heights of cable television.

The $787.5-million defamation settlement last week meant that neither Fox Corporation chairman Rupert Murdoch nor hosts such as Carlson would have to testify in what was expected to be an explosive trial.

But internal Fox News communications released ahead of the scheduled trial had suggested senior figures at the network were prepared to spread falsehoods about the election for fear of losing viewers to rivals.

In the messages, Carlson also said he couldn't wait until he could "ignore Trump most nights," adding: "I hate him passionately."

Dominion, a voting technology company, sued Fox for airing false claims that its machines were used to steal the 2020 presidential election from Trump.

Carlson's relationship with Trump appears to still be close, with the former president sitting for a friendly hourlong interview on the show on April 11 after being arraigned on criminal charges in New York.

Despite the criticism Carlson engendered, Fox News had previously backed him at all costs as he generated a welcome flood of controversy, media attention, viewers and advertising revenue.

The network's lawyers argued in a 2020 slander lawsuit that viewers knew to treat material on his show with skepticism.

In contrast to the political influence he has wielded, Carlson lives far from the heart of the U.S. government, in a rural corner of Maine, where he sometimes broadcasts his show.

He appeared relaxed and confident during his last appearance Friday evening, and his sudden departure shocked Washington and Wall Street, with Fox News' share price falling nearly four percent.

Carlson has long attracted reports that he would seek to enter politics but previously dismissed suggestions he had presidential ambitions, saying "I'm a talk show host; I enjoy it."