Due to an unfortunate childhood trauma, the prospect of festive assemblies leaves me queasy. We were staging the nativity. Outraged that I was not picked for the leading role of the Virgin Mary, I decided to throw myself wholeheartedly into being the Angel Gabriel. This was to prove my downfall. Literally.

I went to town on my costume, feeling gleeful that Mary’s robe was a plain navy blue sheet, whereas I had wings, a silver frock with sequins and a magnificent tinsel halo that bobbed resplendently. As I mounted the stage to deliver my proclamation, the combined weight of wings, glamour and ego tipped me backwards and I fell off.

So it is with some trepidation that I volunteer my form group to do a festive assembly. Even more daring, I decide to delegate the entire project to George and Daniel, the resident drama darlings, and give them creative free rein. Will I never learn?

Our theme is giving, not simply receiving. We decide to ask each pupil in the year group to donate Pounds 1, which we will send to the charity Action Aid. For Pounds 8, we can get cocoa tree seedlings; for Pounds 10, we can buy a flock of chickens; Pounds 28 gets a village two goats. The pupils want to know if there’s a buy-one, get-one-free offer on the goats, but I have to tell them it doesn’t work in quite the same way as shopping here.

The plan is to stage an African village scene. Every pupil in the form offers to help. We have five chickens, four goats, three cows, two sheep and one lamb. All we need is a partridge in a pear tree and we will have a full festive farmyard set.

In an attempt to set a good example, I also offer my services. The cast list is announced and I’m slightly taken aback to be told that I’m to be Maria Carey. How does she fit into our village scene, I enquire? Then I’m told that I will be singing. Alone.

When I try to politely protest, I am told that I can sing.

“We hear you in assembly, Miss.”

Well, yes, they do, but that’s only because no one else in the form is singing. It doesn’t mean that I can sing - only that I make a noise.

Costumes are discussed. The pupils agree to make animal masks and I destroy my feather duster to stick feathers on the chickens. Danielle is the chicken egg and makes a cardboard costume with the word Egg in bold capitals across the front, just in case there is any confusion.

I assume I won’t need to dress up if I’m singing. Wrong. I’m asked if I could wear something like Maria would. “You know, Miss, lots of sequins, sparkle and maybe some fringing.”

Fringing? I’m going to look like a Strictly Come Dancing wardrobe malfunction.

Morning registrations are spent practising mooing and clucking. The room sounds like a cross between Animal Farm and The X Factor.

Even the trees practice waving their arms as branches. I manage to stop them pulling the biology lab plants to pieces to use as foliage.

“When is the last posting date for Christmas, Miss?” Bemused, I ask why. “Well, we need to get that goat to them before the 25th, won’t we?”

I explain, to much disappointment, that it isn’t actually us posting the goat to the village in Africa.

“Why can’t we post it, Miss? We can cover it in bubble wrap. It’ll be OK, honest.”

Bubble-wrapped goats. I make a mental note to let the head of personal, social, health and citizenship education know that there is a potential pastoral topic that needs covering.

“What’s its name?”

Whose name, I wonder?

“The goat, Miss. Can we call it Geoffrey?”

We move on and talk about child poverty, the serious issue behind the fun of the assembly, and how poverty and disadvantage is the biggest determinate of life chances. “Wouldn’t happen here though, Miss, would it?” Wouldn’t it?

I watch the Cutting Edge documentary “Rich kid, poor kid” and weep for the five-year-old boy who has never had his own bed. The boy who has always slept on the floor with the family dogs. The boy who has never been to school. In our city. Not thousands of miles away. In our country that has had 60 years of the welfare state and a century of free comprehensive education. How can this be? Because, despite the rhetoric of policy and the gloss of statistics, family income and status are by far the most significant correlates of success in the school system.

At Christmas we think of others. At Christmas we are charitable to others. Maybe this Christmas we need to do that a bit closer to home.

Julie Greenhough, Teacher of English at a London independent school.