The U.K.'s retail sector had its worst showing on record in 2019, with annual total sales slipping into contraction territory for the first time, the British Retail Consortium said.

Total annual retail sales fell 0.1% in 2019, data from BRC and advisory firm KPMG showed, following a 1.2% growth rate logged in 2018. This marked 2019 as "the worst year on record and the first year to show an overall decline in retail sales," said Helen Dickinson, chief executive of the BRC.

Dickinson said the retail sector suffered from job losses, shop closures and company restructurings in 2019, as uncertainty over Brexit and national politics weakened consumer demand. Retailers also faced challenges from the growth of online shopping and more-cautious spending among consumers amid economic uncertainty, Dickinson added.

The fall in 2019 total sales was driven by a 0.9% drop in sales during the last two months of 2019 compared with the year-ago period, the BRC said, adjusting for data distortion brought about by the late timing of Black Friday in the U.K. At the same time, online sales grew 2.6% in November and December 2019.

Sales on a like-for-like basis fell 1.2% in the last two months of 2019 compared to the same period in 2018. Like-for-like data compares sales from shops that were open the previous year, thus removing the effects of business expansion on sales numbers.