Social media executives could be held personally liable for harmful content distributed on their platforms, leaked plans for a long-awaited government crackdown obtained by the Guardian reveal.

There has been growing concern about the role of the internet in the distribution of material relating to terrorism, child abuse, self-harm and suicide, and ministers have been under pressure to act.

Under plans expected to be published on Monday, the government will legislate for a new statutory duty of care, to be policed by an independent regulator and likely to be funded through a levy on media companies.