Sainsbury’s is encouraging shoppers to ‘Make Believe’ in the run up to this year’s World Book Day on 7 March.

The retailer, which said last year’s event generated more than £1m in sales, is promoting children’s fancy dress costumes associated with book characters. It also plans to host reading corners in larger stores and invite schools to listen to authors and storytellers.

It told staff the day was fast becoming the second-biggest opportunity for kids to dress up after Halloween. Disney Princess and superhero outfits are expected to be this year’s bestsellers.

“We’ve seen a large growth in sales of children’s outfits based on books during our Make Believe event,” it said.