With an estimated nine million pet dogs and eight million domesticated cats in the UK, stores are keen to cash in on festive share of the annual £5.4bn pet market. Advent calendars are a key part of the market and there is even an Advent calendar for rabbits and hamsters. However, the options for humans are more limited.

Out of the 20 million calendars produced for human consumption, less than 400,000 carry any mention of the Nativity, only two brands are Fairtrade and only one is charitable.

David Marshall, from the Meaningful Chocolate Company, manufacturers of The Real Advent Calendar, said: "Stores are happy to cater for pet owners but don't think Christians want to give children a quality Advent calendar which connects with the Christmas story – it's barking."

The Real Advent Calendar is the UK’s only Fairtrade, religious, charity option.

"Parents or grandparents looking for a calendar with religious or ethical content usually find nothing but superhero-themed calendars and £1 cheap chocolate versions on offer," said Marshall.

"Virtually no religious chocolate Advent calendars are on the market. There is a demand for them but they are not stocked by most major stores."