Sources say hardline measures will also prevent young users from being able to talk to strangers on gaming apps

• Why is the UK launching an ‘Australia plus’ social media ban and how will it work?

Keir Starmer is to ban under-16s from major social media apps such as TikTok, Instagram and X in sweeping restrictions described as “Australia plus”, the Guardian understands.

In a major policy shift far tougher than previously briefed, the prime minister will announce that teenagers will be banned from all the main social platforms. Online products that are not covered by the ban – such as gaming apps – will face new restrictions such as having the option to chat to strangers removed.

Measures to include restrictions on ‘safe’ social media apps, with some fearing banning some platforms and not others will lead to legal challenges

Teenagers under the age of 16 are to be banned from accessing “high-risk” social media apps while safer platforms will be subjected to restrictions, under a sweeping government crackdown.

Under-18s will also be banned from using romantic or sexual AI chatbots after a consultation on keeping children safe online.

Prime minister announces ban, saying social media is making children unhappy and unsafe

• Social media to be banned in UK for under-16s, Starmer announces

Starmer acknowledges some teenagers will get round these restrictons. But that does not make the rules pointless, he says.

Will it mean that no child ever looks at social media again? No.

But look, this might shock you, but it doesn’t shock parents of teenagers; they get around other laws too.

Some technology companies want us to think that social media is unchangeable, part of an almost natural order.

But we have to resist that kind of learned helplessness. We have agency, we can change it, and we will.