Try as we might with our Isaac, aged five, between 3ft 10ins and 4ft tall, medium build, with blond unkempt hair and last seen wearing blue Postman Pat pyjamas (it feels natural to describe him as I would a suspect in a crime), he is a tricky customer to control.

Which is where Santa comes in.

My wife decided this week to harness the power of the Christmas list and Santa to tame the boy.

Having written the list of goodies he wants for Christmas, Isaac was disappointed to find it still lying in the fireplace a week later.

For the record, his first Christmas list – there have been several redrafts – was an eye-opener. He wanted five rabbits, two dogs, a tortoise, six sheep, three ducks, four cats, seven newts and a goldfish. A goat we noticed had been crossed out.

"Why no goat?" my wife asked. Isaac looked at her with some amusement: "We can't have a goat in the house … that would be silly."
Sheep and ducks fine: but goats? Get a grip.

He'd also added that he wanted a baby sister … my wife crossed that one out.

"Unless you are a good boy," he was warned, "Santa will not take the list away. And if he doesn't take it away, you won't get any presents."

The omnipresence of Santa was pointed out to Isaac on several occasions. "Santa knows when you're being naughty. He can see you."

Despite the warnings, every day Isaac would do something naughty. And every morning he would run down stairs all excited, only to trudge back with the solemn news that his letter was still there in the fireplace.

"Well, you were warned." The drip, drip effect began to work. By the end of the first week he was back to reasonably acceptable behaviour.

He peaked on one particular day and … Santa took his letter. (For Santa read me being sent downstairs at the crack of dawn to hide his letter).

The breathless cry of "He's taken it, Santa's taken the list" which burst from our boy's lips on opening the front room door was a joy to hear.

He fair exploded into our bedroom to report the news and the miracle of the Christmas list punctuated conversations throughout the day.

Twenty four hours later and he was back to his naughty best.

The Santa obedience plan had worked, but now the list had gone, our Isaac was free from his good boy shackles.

He didn't say it, but it was clear by his behaviour that our Isaac was confident he had achieved immunity from Santa toy sanctions now the Big Man had his list.

Well, it was good while it lasted, I said. Santa had done his bit, but what more could be done? Michelle wasn't prepared to let the matter drop. She once again called upon the power of Santa.
A new warning was issued. "If you continue to be a naughty boy, Santa will return the list."

We were entering uncharted territory. It's a dangerous game to play with the Santa myth. I mean, how far do you go? Forget the God Complex, my wife had developed a Santa Complex.

As her stooge, I was despatched not only to return Isaac's list, but to compose a return letter from Santa outlining his reasons for the rejection.

"Do I carve the message out on tablets of stone?"

My wife dictated the letter. She began by informing Isaac that Santa and the elves had been working very hard at the North Pole preparing for Christmas.

She then cut to the chase. It had come to Santa's attention that Isaac had been naughty and, as such, his list had been returned. It would not be picked up again until his behaviour improved.

In short, he had been removed from Santa's list of Good Boys and, as such, would not be receiving any toys. Santa would, however, keep his name on file and be in touch should the situation improve.

I stuck a cartoon Santa face at the end of the letter and wished him all the best.

Isaac discovered his list and his letter from Santa the next morning.

It was read to him with suitably dramatic intonation by my wife. She gasped and put her hand to her mouth at regular intervals as if reading it for the very first time. You'd think she was reading a ransom demand from the Mafia.

He's now on his best behaviour again, but must think he's trapped in a U-certificate Orwellian Christmas Nightmare. I know I do.

I feel we are being dragged into the unknown. His brother, aged eight, now wants to know why he hasn't got a letter from Santa.

Who solves that one? Don't ask me, I'm just Santa's PA … you'd better ask the boss.