Sales of most fast-moving consumer goods (FMCG) are expected to increase by 35% or more in the week before Christmas.

The sorts of items that fly off the shelves aren't just bottles of wine and wrapping paper, however. Sales of tomato ketchup, mayonnaise, and air fresheners are generally up 40% over average for the week from 18 December to 24 December. Bouillon cubes and gravy go up 60%. Dishwasher tablets, plastic rubbish bags, kitchen towels and butter all go up by around 30%.

Moreover, the experience of going into the shop and buying dozens of other items you didn't realise you needed is universal.

"A very high number of product purchases - more than 50% - are from decisions made in the store rather than noted on any shopping lists, " according to ACNielsen managing director Tom Harper.

With such a surge in demand, Harper warns that staff have to be on their toes less stocks run out and sales are missed.

ACNielsen says that if the brand a consumer is looking for runs out, it's not guaranteed they'll swap for a competitor brand - they just opt not to buy.

"This is a big week for people in all kinds of retail, " said Harper. "If you booze, you lose."