Instagram and other social media giants could be fined billions for breaking the new rules DADO RUVIC/REUTERS

British children will no longer be able to “like” posts on Facebook and Instagram under plans for strict rules that will force social media giants to protect children online.

A code of conduct drawn up by the data watchdog is set to impose conditions on how technology companies treat under-18s, with the threat of fines totalling billions of pounds.

The measures, to be introduced by the Information Commissioner’s Office, come after strong criticism of tech giants by MPs and public figures. The Duke of Sussex warned this month that social media was “more addictive than drugs and alcohol”.

The 16 planned requirements include a ban on “nudge” tactics that encourage children to spend more time on apps, allowing companies to collect more data. The code…