Retailers suffered a "lacklustre" July as expectations of an Olympic boost appear to be "wide of the mark", a leading survey shows.
Sales values edged 0.1% higher on a like-for-like basis in July, compared with a 0.6% rise in the same month last year, the British Retail Consortium and KPMG research said.
Warm weather in the final week and a slight boost from Olympic fever helped support food and drink sales but it was not enough to offset the impact of lower prices and wet weather earlier in the month.
Some retailers did benefit from the longer Sunday opening hours brought in for the Olympic period, the BRC said.
Helen Dickinson, head of retail at professional services firm KPMG, said July was a lacklustre month.
"Central London's retailers are already being hit hard by shoppers actively avoiding the capital. It's likely that any blip of benefit the Games bring will be short-lived," she added.
Total sales, including new stores, were up 2% compared with 2.5% in July last year, while the three-month rolling average shows growth of like-for-like non-food sales outpacing food sales for the first time.
So-called big-ticket items such as furniture and household appliances continue to struggle to sell with growth being promotion-driven.
Online, mail-order and phone sales of non-food items show stronger growth, up 15.6% against growth of 9.6% last year.
Stephen Robertson, BRC director general, said: "There was a boost for food retailers towards the end of the month as the sunshine came out and shoppers started getting in party food and drink ahead of the Olympics but it wasn't a significant help.
"With only the opening couple of days of the Olympic Games covered by these statistics, we'll have to wait a while to assess the overall impact on retail sales."
Last week David Cameron urged people to "come back into the capital" following claims that the 2012 Games has turned London into a "ghost town".
John Lewis, an Olympic sponsor, said sales at its flagship Oxford Street store dropped 8.7% in the week to July 28, while Next said its London stores would "suffer" at the hands of the Olympics.