School bullies who use text messages to terrorise victims could be expelled under tough new government rules.

A Department for Education and Skills (DfES) guidance paper on school bullying, due to be issued to schools in September, will officially recognise the phenomenon for the first time.

It suggests that victims should keep the message or a record of it as evidence, and that mobile phone operators should change a victim's number free of charge if they can prove that it is being abused.

A DfES release announcing the move said that statistics from The National Children's Home published earlier this year showed that a quarter of young people had been threatened via the internet or mobile phone.