Retail sales slid 1.8 per cent on a like-for-like basis in February, according to the BRC-KPMG Retail Sales Monitor.
Total sales grew by 0.1 per cent.
This fall compares with a like-for-like advance of 1.1 per cent in January, when total sales climbed 3.2 per cent.
In the three months to the end of February, like-for-likes dropped 1.4 per cent. Food like-for-likes slowed to 4.3 per cent, partly driven by inflation, according to the c figures.
In the three-month period, non-food like-for-likes slid 5.3 per cent, as January's clearance boost faded. The BRC said homewares and big ticket items were hit "particularly hard".
Total sales across all categories increased 0.6 per cent in the three month period.
Sales in non-food, non-store retailing, which includes sales over the internet, mail order or telesales, climbed 12.3 per cent in February, down from 19.2 per cent in January.
BRC director-general Stephen Robertson said: "These are disappointing figures. It's now clear we were right to fear January's surprise year-on-year sales rise was just a discount-driven blip. Every non-food sector, apart from children's clothes, saw like-for-like sales down on a year ago.
"Early February snow didn't help but customers and retailers' difficulties run deeper. Meanwhile Government stands by. We're not looking for handouts but, from business rates increases to a supermarket ombudsman, we don't need costly new handicaps."
KPMG head of retail Helen Dickinson said: "The women's and men's clothing sectors had their worst month since April 2008, being impacted significantly by the snowy weather in the first week of the month.
"Battling falling sales is not a sustainable prospect for many retailers. More announcements of job losses and other cost cutting measures in the sector look likely in the short term."
