A white paper on online harms, published jointly by the Departments for Digital, Culture, Media and Sport (DCMS) and the Home Office, proposes strict new rules be introduced that require firms to take responsibility for their users and their safety, as well as the content that appears on their services.
It suggests punishing social media companies with large fines or blocking them from being accessed.
Overseen by an independent regulator, internet companies which break these rules could even see senior management held personally liable for the failings.
A newly introduced duty of care will require firms to take more responsibility for the safety of users and more actively tackle the harm caused by content or activity on their platforms.
The regulator will have the power to issue “substantial fines, block access to sites and potentially impose liability on individual members of senior management”, the proposal says.
The Government is currently consulting on whether to create a new regulator or use an existing one, such as Ofcom, to enforce the new rules.
The proposed measures are part of a Government pledge to make the UK one of the safest places in the world to be online, and comes in response to concerns over the growth of violent content, encouraging suicide, disinformation and the exposure of children to cyberbullying and other inappropriate material online.
A number of charities and campaigners have called for greater regulation to be introduced, while several reports from MPs and other groups published this year have also supported the calls for a duty of care to be implemented.
Prime Minister Theresa May said the proposals were a sign the age of self-regulation for internet companies was over.
“The internet can be brilliant at connecting people across the world – but for too long these companies have not done enough to protect users, especially children and young people, from harmful content,” she said.
“That is not good enough, and it is time to do things differently. We have listened to campaigners and parents, and are putting a legal duty of care on internet companies to keep people safe.
“Online companies must start taking responsibility for their platforms, and help restore public trust in this technology.”
Theresa May, UK Prime Minister
The proposed new laws will apply to any company that allows users to share or discover user-generated content or interact with each other online, the Government said, applicable to companies of all sizes from social media platforms to file-hosting sites, forums, messaging services and search engines.
It also calls for powers to be given to a regulator to force internet firms to publish annual transparency reports on the harmful content on their platforms and how they are addressing it.
Companies including Facebook and Twitter already publish reports of this nature.
Last week, Facebook boss Mark Zuckerberg told politicians in Ireland that the company would work with governments to establish new policies in a bid to regulate social media.
The Home Secretary, Sajid Javid, added that tech firms had a “moral duty” to protect the young people they “profit from”.
“Despite our repeated calls to action, harmful and illegal content – including child abuse and terrorism – is still too readily available online,” he said.
“That is why we are forcing these firms to clean up their act once and for all. I made it my mission to protect our young people – and we are now delivering on that promise.”
A 12-week consultation of the proposals will now take place before the Government will publish its final proposals for legislation.
The Government said the proposed regulator would have a legal duty to pay due regard to innovation, as well as to protect users’ rights online.
Peter Wanless, chief executive of children’s charity the NSPCC – which has campaigned for regulation for the past two years – said the proposals would make the UK a “world pioneer” in protecting children online.
“For too long social networks have failed to prioritise children’s safety and left them exposed to grooming, abuse, and harmful content,” he said.
“So it’s high time they were forced to act through this legally binding duty to protect children, backed up with hefty punishments if they fail to do so.
“We are pleased that the Government has listened to the NSPCC’s detailed proposals and we are grateful to all those who supported our campaign.”
However, former culture secretary John Whittingdale warned ministers risked dragging people into a “draconian censorship regime” in their attempts to regulate internet firms.
Writing in the Mail On Sunday, he said he feared the plans could “give succour to Britain’s enemies”, giving them an excuse to further censor their own people.
“Countries such as China, Russia and North Korea, which allow no political dissent and deny their people freedom of speech, are also keen to impose censorship online, just as they already do on traditional media,” he said.
“This mooted new UK regulator must not give the despots an excuse to claim that they are simply following an example set by Britain, where civil liberties were first entrenched in Magna Carta 800 years ago.”
Responding to the proposals, Facebook’s UK head of public policy Rebecca Stimson, said: “The internet has transformed how billions of people live, work and connect with each other, but new forms of communication also bring huge challenges.
“We have responsibilities to keep people safe on our services and we share the Government’s commitment to tackling harmful content online. As Mark Zuckerberg (Facebook’s founder) said last month, new regulations are needed so that we have a standardised approach across platforms, and private companies aren’t making so many important decisions alone.”
She added that while Facebook had tripled the number of people it employs to identify harmful content and continued to review its policies, “we know there is much more to do”.
“New rules for the internet should protect society from harm while also supporting innovation, the digital economy and freedom of speech. These are complex issues to get right and we look forward to working with the Government and Parliament to ensure new regulations are effective,” she added.