During an exchange live on air on Sunday, Ms Willoughby said: “I don’t want to be involved anymore because having watched a week of output from the station it’s quite clear to anyone that you’re anti-trans.”
She had previously agreed to appear weekly on the news channel as a panel commentator on Tonight Live with Dan Wootton.
GB News launched earlier this month and is the first news channel in the UK to generally be considered to have an explicit political orientation.
Ms Willoughby told PinkNews that this was something that had initially appealed to her, as she described herself as a “patriotic person” with “right of centre political views.”
“I was really looking forward to doing it,” she said. “I thought it was going to be a breath of fresh air. I like debates.”
She said that in reality, the channel was nothing like her expectations, describing her experience as “an absolute nightmare”.
“For people like me, it’s opened the gates of hell,” she said.
Throughout the month of June, GB News had hosted voices such as Maya Forstater, who recently won an employment tribunal after losing her job over tweets claiming trans women are “not women”, and the LGB Alliance , an organisation that opposes policies on trans issues, which has been accused of being “transphobic” by a number of MPs.
Writing in the Mail+ on Wednesday, Ms Willoughby said: “All I wanted to do was present a passionate defence of trans people (of whom I am one) after a week of unrelenting negative media coverage…”
She said that she felt frustrated that there had been a lack of balance and hoped to correct views that trans people were “dangerous and deluded”.
“After all,” she wrote, “GB News was the station looking for previously silenced voices.”
Ms Willoughby said she decided to quit GB News following her initial on-screen interaction with host Dan Wootton on Sunday.
When Mr Wooton introduced Ms Willoughby as “trans broadcaster India Willoughby,” she replied, “It’s great to be with you, gay presenter Dan Wootton”.
“I didn’t want to be part of what I considered the demonisation of a section of society with no representation,” she wrote.
Sunday night’s episode of Tonight Live with Dan Wootton which features Ms Willoughby is not currently available on GB News’ website.
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