"With such a weak base for December 2015 (when sales fell 5.3 percent) any further decline can only be seen as a poor result for retailers," said Sophie Michael, head of retail and wholesale at BDO.
"Coming at a critical juncture, this fourth negative December in succession highlights the magnitude of the challenge that lies ahead for 2017, when consumers will more keenly feel the bite of inflation and the weaker pound," she added.
Sales of fashion goods declined 1.07 per cent in December, but the overall figure was pushed toward parity by like-for-like increases in the lifestyle and homewares sectors, up 2.4 per cent and 2.6 per cent respectively.
BDO said that in the week leading up to Christmas Day sales increased 11.7 per cent year on year, helped by Christmas Day being a Sunday.
British Retail Consortium figures for December come out on 10 January. BRC has said November sales rose.