Millions of Americans cut short Thanksgiving to head to shops that opened earlier than ever as retailers fought for holiday sales as economic anxiety hung over one of the biggest shopping days of the year.

Up to 152m people plan to shop over the three days after Thanksgiving, according to the National Retail Federation, with many queueing under the stars to secure “door buster” discounts unveiled on the day known as Black Friday.

Black Friday sets the tone for the end-of-year shopping season, which in turn is a make-or-break period for many US retailers struggling to defend market share as unemployment and a weak housing market keep consumer sentiment fragile. Shopper surveys have suggested holiday spending this year will rise by between 2 and 4 per cent from last year.