It was just a home-made bridesmaid dress, but I’ve never forgotten the heartache it caused. I was seven years old, looking forward to my first Christmas party at primary school. My mum, who was at work, had arranged for a neighbour to take me home at lunchtime so I could change into my party dress.

Somehow, crossed wires led to my teacher refusing to let me go home. I remember pleading with her, trying to explain that it had all been arranged, but she insisted I was on the school dinners list and had to stay.

So instead of going to the Christmas party that afternoon in my beloved bridesmaid dress, I was stuck in my school uniform. The other girls had either brought party outfits that morning or gone home to change.

I’ll never forget how humiliated I felt as we trooped into the school hall for the party; them in their long frilly frocks and me in my navy blue pinafore-dress and cardigan. I was heartbroken. It seems trivial now, but it was a small taste of how it feels to be alienated from a peer group, which is the last thing you want as a child.

I wasn’t bullied at school, but I saw it going on, and usually it was because the victims looked a bit different or weren’t wearing the right clothes.

Girls have always been catty and cruel, but a recent survey by Bradford-based charity Rathbone suggests that bullying is becoming more sinister.

More than half the teenage girls surveyed had been bullied, with some punched and kicked “simply because they couldn’t afford the best clothes” or humiliated on the internet because of weight and even hair colour.

Rathbone spokesman Peter Gibson says “there’s far too much pressure on young women to look a certain way”.

Surely the ludicrous ritual of the school prom doesn’t help. Somehow, over recent years, a tradition which started in elite American colleges in the 19th century has become a rite of passage in British schools.

Countless times I’ve driven past teenagers in strappy gowns and tuxedos climbing in and out of stretch limousines. The girls look like mini-WAGs and the boys look, frankly, daft.

I know it’s exciting for them – my 12-year-old niece is practically counting the days until her first prom next year – but it’s such a flashy affair. Ballgowns, designer suits, limos, fake tans – there must be enormous pressure on youngsters to look the part.

In an age when children are driven to suicide because of bullying, it seems grossly inappropriate for schools to embrace such a materialistic, potentially divisive ritual for those barely in their teens.