Andrew Neil has resigned as chairman and lead presenter of GB News, just three months after helping to launch the channel.
Neil, 72, was on air for less than two weeks before announcing he was taking a break.
The former BBC political presenter will continue to contribute to GB News as a regular guest commentator.
In a statement, he said he had decided to "reduce my commitments on a number of fronts".
He added: "Over the summer I've had time to reflect on my extensive portfolio of interests and decided it was time to cut back."
"I wish GB News well in continuing to fulfil its founding promise and mission to reach audiences currently underserved by existing news broadcasters."
It’s official: I have resigned as Chairman and Lead Presenter of GB News.
— Andrew Neil (@afneil) September 13, 2021
The BBC is not responsible for the content of external sites.View original tweet on Twitter
A statement from GB News said: "Andrew is without doubt one of the finest journalists and interviewers in this country.
"GB News thanks him for his 12 months of leadership, wisdom and advice, and we wish him well."
Neil left the BBC after 25 years following the US presidential election last November.
He then turned his attention to launching GB News in mid-June, with the channel promising to "change the face of news and debate in the UK".
However, he was said to have gone on leave at the end of June. He did not return, and earlier this month it was reported that relations between Neil and chief executive Angelos Frangopoulos had broken down over the direction of the company.
The network recruited former UKIP leader Nigel Farage in his absence, to join ex-Sun journalist Dan Wootton and experienced news anchors Simon McCoy and Alastair Stewart, who were recruited from BBC and ITV respectively.
Neil's departure comes two months after Guto Harri quit the network following a row over his decision to take the knee during a discussion about racism towards England's black footballers.