In a report on the effects of online intermediaries – including search engines, social media platforms and aggregator services – on media plurality, Ofcom found that Facebook was the most commonly cited intermediary used a source of news, followed by YouTube, Google Search and Twitter.

Research for the report suggests that people who mainly used social media to access news are more likely to be less tolerant of opposing political views, less able to correctly identify factual information and less trusting of democratic institutions, compared to those mainly using TV and newspapers.

However, the same patterns did not generally apply to those most often using search engines or news aggregators.

The study also found there was confusion among participants about whether news online is personalised: 35% of people think it is, 36% think not, and 29% are unsure.

Research for the report included a quantitative survey of 2,500 people, passive tracking of 1,000 people’s devices and deliberative online focus groups.

The scale of potential sources available for news may be “overwhelming” and mean that trustworthy content struggles for space and attention alongside “more sensationalist and unreliable material”, Ofcom said in the report.

The regulator added: “As intermediaries increasingly play the role of gatekeepers, curating or recommending news content to online audiences, it is not clear that people are aware of the choices being made on their behalf, or their impact.”

Ofcom is planning to develop recommendations for the government, which could include tools requiring technology companies to be “more transparent” about how they determine what news the public see online. Any decisions about whether new laws are needed are ultimately a matter for government and parliament. 

Ali-Abbas Ali, competition director in Ofcom’s broadcast and online content group, said: “Our news landscape has seen huge transformation over the last decade, with online firms offering easy access to an ever-wider pool of stories, voices and opinions.

“But while there’s no lack of choice, new concerns are emerging about the impact of the decisions that tech firms make on our behalf to determine the news stories we do – and don’t – see in our feeds.

“We’re undertaking further work to interrogate this issue and expect to make formal recommendations to government to ensure the UK’s diverse and vibrant news landscape is secured for the future.”