High street sales have experienced their biggest fall in more than a decade as consumers "confront reality", a report has warned.

The monthly retail sales monitor recorded a "worrying" 1.5% drop in total sales in January, compared with the same month last year.

This was the biggest fall in total sales since 1999.

Consumer confidence in Scotland remained lower than the UK as a whole, with sales falling faster than anywhere else in the UK.

Officials at the Scottish Retail Consortium (SRC) called it "a sign of troubled times" while professional services firm KPMG said the "concerning" figures are "indicative of the challenges which the retail sector will face in 2012".

Big discounts and clearance sales in January failed to overcome consumer caution, with non-food sales showing the biggest fall since the survey began in 1999.

The poor non-food sales outweighed the more encouraging food sales, with big-ticket homeware goods especially hard hit.

SRC director Ian Shearer said: "A sales decline on this scale sets alarm bells ringing for Scottish retailers.

"Combined, as it is, with some above-inflation cost pressures, there are potentially worrying implications for Scotland's largest private-sector employer."

Like-for-like sales, which excludes new stores, were 2.6% down on last year, the worst decline since last May and the ninth decline in the last year.

As in the UK results, both like-for-like and total sales worsened in January after a better December. By both measures, sales fell more quickly in Scotland than elsewhere.

Mr Shearer added: "Customers have confronted reality again since Christmas.

"Consumer confidence remains low, Scottish household incomes are being squeezed by increased utility and fuel prices, and continued fears over job prospects and the wider economy are front-of-mind for many - deterring purchases which are not immediate needs.

"The biggest year-on-year drop in overall sales in over a decade is a sign of troubled times for retail."

David McCorquodale, head of retail in Scotland at KPMG, said: "Already in 2012 we have seen several big-name retailers fall victim to the tough trading environment and unfortunately this trend looks set to continue as consumer confidence continues to waver in the face of economic uncertainty and widespread worries about job security."