UK High Street sales fell to a 14-month low in May, according to a survey by the CBI business group.
Its monthly distributive trades survey reported a sales balance of -18 in May from +13 in April.
Bad weather and a slowdown in the housing market cut consumer demand, the survey said.
"These retail sales figures for the early part of May are clearly disappointing," said Ian McCafferty, the CBI's chief economic adviser.
He said poor weather at the start of the month was likely to have dented clothing sales.
In addition, Mr McCafferty said signs of "slowing momentum" in the housing market may have been behind "renewed weakness in sales of big-ticket items and other household goods".
The CBI's reading was below what analysts had expected.
"The CBI survey reinforces our long-held concern that the upside for consumer spending, and hence growth, will be limited for some time to come as households still face very challenging conditions," said Howard Archer, chief UK economist at IHS Global Insight.