Teachers are facing “vile” abuse from children as young as seven on social networking websites such as Facebook, Twitter, You Tube and Instagram, according to research.

Figures show that more than a fifth of teachers have been the victim of “cyberbullying” from pupils and even their parents in the last year.

The study showed social media was being used to make offensive remarks about teachers’ personal appearance, classroom performance and sexuality, with websites also used to circulate malicious claims about alleged inappropriate behaviour and drunkenness.

In one case, pupils set up a bogus Facebook account in a teacher’s name, saying: “I will rape every Year 8 pupil who comes to the school.”

Other pupils found a picture of an unconscious drunk who resembled a particular teacher – then posted it on Twitter and distributed it to other children.