The survey shows that of the 3.6 million 7 to 16s who currently own a mobile, 14% have received a bullying or deliberately hurtful call or text message on it. The problem is at its worst among 14 to 16-year-old mobile phone owners, one in five (21%) of whom has been on the receiving end of nasty calls or messages.

Bullying calls or text messages are slightly more likely to come from people known to the victim. However, somewhat more frighteningly, around a quarter of a million kids claim they have been victimised without knowing the source of the call or message. Only some 6 out of 10 victims say they would tell a teacher, a parent or the police in the event.

Barbie Clarke, director of NOP Family, said, "Schools have been working hard to clamp down on bullying wherever they see it, but we appear to be witnessing the first signs of a particularly nasty form of it. It is well known that kids love their mobiles, but kids can also be very cruel and parents and schools need to act swiftly to stamp this out before it becomes more widespread."