He says he wrote the song at home and finished it in a branch of Safeway while he was waiting for his mum to finish her shopping.
Now more than 150,000 people have ordered copies of the single, which is normally around double the amount of sales needed to go to number one.
Competition is already tough
Robbie and Nicole's hope for number one, Something Stupid, is released this week and is expected to go straight to number one. But it will need to hold on for a second week to celebrate 25 December at the top spot.
The competition is already tough, with Cliff Richard, Emma Bunton, The Lampies and both Janet Jackson and her brother Michael releasing records.
S Club 7 are currently your favourites in our Xmas number one vote. Click on the link at the top right of the page and get voting!
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Who should be Xmas number one?
