UK retail sales fell by 0.1% over the past 12 months, figures from the British Retail Consortium revealed.
Total sales in October were down 0.1% on the figure for the same month in 2007 - the first yearly drop since April 2005 - while like-for-like sales, which do not include new outlets, fell by 2.2%.
The figures suggest the credit crunch is having a marked impact on consumer spending, and adds to the feeling that this Christmas will be particularly tough for retailers.
"These are seriously poor numbers, especially in the run-up to Christmas," said the BRC's director general Stephen Robertson.
"Like-for-like sales have now fallen in seven of the last eight months, with every sector down on a year ago apart from food and footwear."
Retailers will hope the Bank of England's decision to cut interest rates by 1.5% earlier this month will lead to greater levels of spending over the next two months.