SOCIAL media giants risk being told to “open up or break up” in 2018 as fears over fake news approach boiling point, a leading academic has suggested.

“It may well be that this is the beginning of the end for these firms,” said Dr Damian Tambini, director of the London School of Economics’ (LSE) media policy project.

The days of social networks enjoying an ability to shift public opinion, while remaining largely free of the liabilities publishers face, may be numbered, he said.

He added: “For these super-giant companies it’s got very serious now. They have to face up to the fact they’re coming up against existential problems in liberal democracies.

“They should at least clarify the principles behind how their algorithms rank news, because when they tweak it they effectively become something between an editor and a censor, particularly given their monopoly position.

“They have enjoyed this ability to use our data, our content, our innovation, to create huge businesses and we have given them a shield from a lot of the risks.

“So essentially we made them — is this the year that we begin unmaking them?”

Leading social media companies have been criticised recently over their replies to a parliamentary investigation into fake news and allegations of Russian interference in British politics.

Twitter’s response was described as “completely inadequate” by Damian Collins, chairman of the Commons Digital, Culture, Media and Sport Committee, while he accused Facebook of doing virtually “no work” to help the probe.

Meanwhile, Professor Charlie Beckett, leading LSE’s new Truth, Trust and Technology Commission, compared the fake news phenomenon and proliferation of junk information to air pollution.

He said: “You can either ban all cars because that solves the problem, or you try to make the cars cleaner, regulate traffic.”