The Olympics failed to boost spending in August, when retail sales were at their lowest level in nine months, the BRC-KPMG Retail Sales Monitor showed.

The net effect of the Games was “minimal”, said the BRC, as like-for-like retail sales values edged down 0.4% compared to a year earlier when they slipped 0.6%. Total sales rose 1.6% in the month, which produced the worst performance this year once the timing of Easter is taken into account.

The poor performance reflected weak non-food sales. Women’s clothing, furniture and home related items did particularly poorly. However the Olympics drove an uptick in food sales as shoppers celebrated the sports spectacular.

Online sales did not escape the Olympics impact either, recording the lowest growth since October 2008 and advancing just 4.8% in the month.

BRC director general Stephen Robertson said: “It’s clear people were absorbed by the magnificent Olympics and had little interest in shopping, especially for major items.

“Usually-reliable online sales suffered, putting in the worst sales growth since we started the measure four years ago. Some retailers told us online activity was particularly thin in the evenings.”

Throughout August, clothing sales were “disappointing” as Autumn/winter womenswear ranges suffered during the warm weather and because of a drop in footfall in central London as a result of the Olympics, later holidays, an early Eid and later back-to-school dates.

Footwear remained the top performing category and some retailers anticipated the trend, increasing stock of key lines such as pumps, and extended the Sale period into August.

DIY and garden retailers welcomed the sunshine and sales of outdoor furniture, barbecues and picnicware were particularly strong in the last week of the month.

KPMG head of retail Helen Dickinson - who was last month named as Robertson’s successor as director-general of the BRC - said: “While, without doubt, the Olympics brought a much needed boost to consumer confidence, the country was ‘otherwise engaged’ in August and the sales figures show a mixed picture.

“However, it could have been much worse. August is traditionally a weak month for sales and it’s really the next three months that will have a critical impact on retailers’ profitability.”