The Ministry of Stories is inviting budding story tellers to finish off a yarn by Horrid Henry author Francesca Simon about why the Tooth Fairy is fed up and wants to resign.

The start of the story is written on the inside of the brand new chocolate bar, Milk Tooth, which will be on sale for £2.50 in the Monster Supplies shop in Hoxton Street to raise funds for the charity’s work improving children’s literacy.

This Saturday the shop will host a fantasy recruitment fair to find the Tooth Fairy’s successor between 2pm to 4pm, and wants children of all ages to come along and apply.

Finishing off Ms Simon’s story is part of the application process.The Ministry of Stories was founded three years ago by Fever Pitch author Nick Hornby and co-directors Lucy Macnab and Ben Payne.

Hidden away at the back of The Monster Shop and run by volunteers the idea is to inspire children in creative writing.

Milk Tooth is described as a deliciously smooth milk chocolate made with chunks of delicately roasted milk teeth.

“Gathered by a skilled team of tooth fairies, and made with only the finest quality molars, children are always paid a fair price for their gnashers,” reads the blurb on its wrapper.