Ofcom will soon be able to punish social media companies for potentially harmful material on their platforms, with the government set to appoint it as the new online safety regulator.
Culture Secretary Baroness Nicky Morgan and Home Secretary Priti Patel said Ofcom's existing position as a regulator made it suitable to enforce rules to keep the internet safe.
The broadcasting regulator, which already has powers across the television, radio and telecoms sectors, said it shares the government's "ambition to keep people safe online".
When the government appoints the regulator to the role it will be able to fine social media companies which do not protect users from harmful content.
Ofcom's interim chief executive, Jonathan Oxley, added: "We will work with the Government to help ensure that regulation provides effective protection for people online and, if appointed, will consider what voluntary steps can be taken in advance of legislation."
The regulator has also announced the appointment of a new chief executive, civil servant Dame Melanie Dawes, as part of its preparation for a new, wider role.
The government decision on Ofcom was published as part of an initial response to a consultation on the government's online harms white paper which was released last year and called for a statutory duty of care for internet companies to protect users against potentially harmful content.
Those proposals suggested allowing the regulator to issue fines against platforms and websites it judges to have failed to protect users from seeing harmful videos such as those depicting violence or child abuse.
The government response said the regulator would have the responsibility of making sure online companies have the systems and processes in place to fulfill the duty of care to keep people using their platforms safe.
Baroness Morgan said: "With Ofcom at the helm of a proportionate and strong regulatory regime, we have an incredible opportunity to lead the world in building a thriving digital economy, driven by groundbreaking technology, that is trusted by and protects everyone in the UK.
"We will give the regulator the powers it needs to lead the fight for an internet that remains vibrant and open but with the protections, accountability and transparency people deserve."
The Government has previously mooted a statutory duty of care for internet companies with an independent regulator enforcing new guidelines against so-called online harms.
A role for Ofcom in dealing with technology firms like Facebook, Instagram and YouTube has previously been suggested and followed the publication of a Government white paper into online harms in April.
Proposals were put forward in August which suggested allowing the regulator to issue fines against platforms and websites it judges to have failed to protect users from seeing harmful videos such as those depicting violence or child abuse.
The suggested Ofcom scheme would serve as an interim arrangement until an online harms regulator is appointed under future legislation.
But the latest proposal could extend the remit of the regulator further with the Government white paper looking to regulate "illegal activity and content to behaviours which are harmful but not necessarily illegal".
Concerns about the impact of social media on vulnerable people come amid suicides such as that of 14-year-old schoolgirl Molly Russell in 2017, who was found to have viewed harmful content online.
Molly’s father Ian spoke of the urgent need for greater action in an emotional foreword to a Royal College of Psychiatrists report, in which he described the "wrecking ball of suicide" that "smashed brutally" into his family, blaming "pushy algorithms".
He said of her social media accounts: "Among the usual schoolfriends, pop groups and celebrities followed by 14-year-olds, we found bleak depressive material, graphic self-harm content and suicide-encouraging memes.
"I have no doubt that social media helped kill my daughter."
Ofcom was established in 2003 and took on duties previously performed by the separate regulators of broadcasting, telecommunications and radio.
Andy Burrows, the National Society for the Prevention of Cruelty to Children’s head of child safety online policy, said: "Any regulator will only succeed if it has the power to hit rogue companies hard in the pocket and hold named directors criminally accountable for putting children at risk on their sites.
"Boris Johnson can protect families and support law enforcement by standing firm against some of the world’s most powerful companies.
"To do that it’s imperative that we have a duty of care model that puts the onus on big tech to prevent online harms or answer to an independent regulator."
Key ways to keep yourself and your children safe on social media:
Assess how and where they use devices: Based on their routine, think about when and where they are using their device to establish when it would be better for them to unplug and focus on other activities. Generally, it is best not to be on devices right before bed or keep them in bedrooms as night.
Examine what they are doing online: Not all online activities are created equal – take the time to assess how particular activities that your child is doing can help or hinder their development as they grow. Ask yourself – Is this activity helping my child achieve a goal, improve their development in a certain area, promote their sense of self, or build-up skills that will help them make smart choices as they grow?
Look at your relationship with screens: Review your own relationship with screens to address how this may be affecting your digital use.Is there anything that you can do in your interactions that will give them the confidence to build a healthier relationship with tech?
Establish a family agreement: Work together to manage expectations of how screens and online platforms should be used and why. For younger children find ways to combine touchscreen use with creative or active play. Children’s screen time does not have to be passive, look for apps that encourage and complement physical activity.
Make use of parental control tools: Use settings on their devices and platforms to set digital boundaries together to ensure they get the best out of their screen time.
Use night settings: Some phones have blue light filters to help reduce the amount of blue light given off by the screen during night-time hours which may help children sleep.
Notifications: Switch off notifications on their phone to limit the distraction this can cause when they are doing other activities
Worried about your online behaviour, or somebody else's? Here are some helpful contacts:
Visit www.stopitnow.org.uk website or call the helpline on 0808 1000 900.
Visit nspcc.org.uk or call the helpline on 0808 800 5000.
If you work with children and young people and are concerned about their online safety you can call the professionals online safety helpline on 0344 381 4772.