Kopparberg and Nivea are among brands that have suspended advertising with GB News amid a social media campaign to boycott the new "anti-woke" TV channel.
Companies advertising with GB News are being lobbied on Twitter to drop all ties with the channel over its perceived right-leaning politics.
Kopparberg responded to a number of Twitter users who criticised its appearance on the channel, with the Swedish drinks manufacturer claiming the “ad ran on this channel without our knowledge or consent”.
It added: “Kopparberg is a drink for everyone and we have immediately suspended our ads from this channel pending further review of its content.”
Watch: Andrew Neil launches GB News
The Open University said: “We’ve not planned or purchased advertising with GB News and are investigating why this has happened. This advertising has been paused with immediate effect.”
Nivea was another company that said its advert appeared “without our knowledge” due to “media buying algorithms”.
The skincare firm told Press Gazette it is pausing its advertising for three months as part of a review “to ensure that they reflect the values we hold as a company”.
Grolsch, the Dutch beer manufacturer, is also reported to have pulled its adverts.
Andrew Neil, the former BBC political interviewer who is chair of GB News and will present his own show on the channel, has previously said he is unconcerned about boycott campaigns.
He told the Evening Standard: “It’s all good publicity. For everybody that wants to boycott there are about 10 people who are going to watch.
“I am not worried about that. It only becomes a problem if you don’t stand up to them and I can assure you we will.”
The channel, which has a number of high-profile presenters, launched on Sunday night, and was given a slot at Boris Johnson’s coronavirus press conference on Monday.
It will be opinion-led, and has positioned itself as a rival to traditional rolling news broadcasters such as the BBC and Sky.
Critics have labelled it a British version of Fox News, the conservative American channel. GB News has rejected this.
Neil, meanwhile, promised in his opening monologue on Sunday: “If you want fake news, lies, distortion of the facts, conspiracy theories… then GB News is not for you.”
He also said it would “puncture the pomposity of our elites in politics, business, media and academia and expose the growing promotion of cancel culture for the threat to free speech and democracy that it is”.
Neil railed against the "metropolitan mindset" of the media, though like most other news companies, GB News is headquartered in central London.
Stop Funding Hate, one of the leading campaigners against GB News, has said of its drive: "GB News' multi-million pound backers can subsidise them if they want to, but that doesn't mean the rest of us have to.
"Brands are free to choose where they do and don't advertise, and the public are free to speak out and seek to influence that choice."
The group – known for previous boycott campaigns against newspapers such as the Daily Mail – has listed companies on its website that have appeared on GB News.
Watch: Tuesday's daily politics briefing