Following a week which saw John Lewis take nearly £100 million in sales, the firm has said revenues of the toy are soaring due to it's evergreen appeal and new product innovations.
Elaine Whiteman, John Lewis toy buyer, told The Evening Standard: "Lego is building up to its biggest year yet.
"Sales are increasing 65 per cent week-on-week thanks to its enduring appeal and exciting brand developments, and we predict Lego will make up 15 per cent of all our toys sales this Christmas."
John Lewis also expects the toy to account for half of all the boys' toys it sells, thanks to a wide range of licensed products, including Star Wars and Indiana Jones.
Lego UK MD, Marko Illincic, commented: "We've trebled the size of our UK business in teh last three years.
"The beauty of Lego is that you can play with it multiple times."
In it's bumper week, John Lewis saw toys and electronics driving sales in the run-up to Christmas. Scooters, Butterscotch the animatronic pony, kids' VTech cameras and the John Lewis wooden kitchen were among the most popular products.
Nat Wakely, director of selling operations for John Lewis, said: 'This week has been very strong. It's clear that shoppers are appreciating the value we offer and our customer service as well as our broad and inspiring offer as they select gifts for all of the family.
"This week has focused not only on small children but those bigger 'kids' too for whom gadgets and electronics are looking like top gifts."