Facebook users will be given a new legal right to wipe clean all photos, messages and information that they put online before turning 18 under a new manifesto pledge announced by Theresa May.

The Prime Minister will announce plans for new legislation to amid concerns that people's career prospects are being damaged by comments they made as teenagers.

Social media companies will also face significant fines if they fail to stop people from "unintentionally" coming across pornography, hate speeches and other harmful material.

They will also be legally obliged to take down "inappropriate, bullying, harmful or illegal content" that is flagged to them by users or fines.

The Tories will also unveil new powers to hit the entire social media industry with a multi-million pound fines if it fails to fulfill its responsibilities to protect users.