All along Oxford Street, London’s central shopping thoroughfare, retailers are adding a new ornament to their holiday window displays: bright red signs that read “50 percent off.”

Fears of a dismal season have mounted since Sports Direct International Plc Chief Executive Officer Mike Ashley said November sales were “unbelievably bad.” Online retailer Asos Plc added to the jitters this week with a profit warning, showing that e-commerce isn’t immune to the downturn. Bricks-and-mortar chains like Maplin and the U.K. arm of Toys “R” Us Inc. collapsed earlier this year.

As the last weekend of Christmas shopping neared, stores slashed prices on a range of items to try to salvage sales. For some customers, accustomed to having to wait until after New Year’s for markdowns, the discounts came as a welcome surprise.

“It’s amazing,” said Chimere Girigari, 26, as she carried four coats among the racks at Forever 21. “I was just walking by and saw the ‘50 percent off’ so I came in.”

Here are five of the markdowns that show how stores are responding to the U.K.’s retail gloom:

Forever 21

Unusually warm weather this autumn prompted steep discounts on winter…