An NSPCC spokesman said: "Preventing harmful sexual behaviour through proper, up-to-date sex and relationships education is immeasurably better than excluding children after the harm has been done.

"By giving children the right information … we can teach them how to treat others and how to know when something is not right."

The spokesman said that the school curriculum should be updated to teach children about the dangers of sexting and online porn.

"Social media, sexting, online porn and dating apps did not exist when sex education was introduced on the curriculum a generation ago," they said.