"MUM, a boy in my class said that Father Christmas isn't real."

My youngest daughter was eager to impart this information the second I collected her from school.

"Of course he's real. How else would you get all your Christmas presents? Mummy and Daddy haven't got time for all that finding and wrapping and things?"

"But how does he get round everyone in the whole wide world?" she persisted.

Fobbing children off is no picnic. They keep on and on and on. They make the interrogators in Spooks seem weak.

It's relatively easy when they're very young, but once they start school and come into contact with early non believers, whose older siblings or even, occasionally parents, have squashed the fantasy, it becomes a struggle.

Aged eight and six, my children both still believe, and I want them to carry on believing for as long as possible. It's nice to think of them picturing Father Christmas and his sleigh whooshing across frosty rooftops, as opposed to me thrashing my way around Argos at a soulless out-of-town shopping centre.

But, I know that the make-believe can't last. This year it's been a bit tricky. Sadly, in this house we have no fireplace (it's on my 'Things To Do When I Win The Lottery' list), although we do have a chimney. The questions as to how Santa will access our home have been coming thick and fast. The children are finally convinced that if we leave the door unlocked he will be more than happy to use it but they are still stressed about how to send Santa a note. My parents have offered to do the deed.

The innocence of children is a wonderful thing, but while they readily accept fantasy, you only need the slightest break from the norm for them to become suspicious.

I remember one night, when my husband and I forgot to take my daughter's tooth from under her pillow and replace it with money from the tooth fairy. I was mortified the next morning when she came crying into our room.

We somehow managed to convince her that the tooth must have been too far under and the fairy could not reach it. But a sliver of doubt was lodged, and her enthusiasm for the task has not been the same to this day.

Belief is a strange notion. My husband thinks that my belief, albeit faltering, in God, is no different to the children's belief in Santa. And when I think about it, there's really no concrete evidence that either exist. When the children ask me about God (and, thankfully, it's not often), I have less of an idea as to what to say as I have about Father Christmas.

So this year we will do it again, the fake snow prints - "still on his boots from the North Pole" - the glass of sherry, the slice of cake and the carrots for the reindeer.

And, as we do when the tooth fairy visits, we will leave a note out for ourselves, reminding us to partake of these things before we collapse into bed at 3am after doing Santa's job for him.

Updated: 11:30 Tuesday, December 21, 2004