Like-for-like retail sales fell back 0.4% in June - the third fall in the last four months - but total retail sales were up 2.1%.
According to the British Retail Consortium's sales monitor, sales of clothing and footwear fell back sharply after May's sun driven boost.
The BRC said that clearance markdowns and a few sunny days had helped summer tops, shirts and dresses but that underlying trade had worsened as squeezed incomes were spent on basic essentials and smaller accessories rather than knitwear, formal trousers and jackets and discretionary items. Top-end designer fashion continued to deliver gains for some. Kidswear outperformed menswear and womenswear.
Men's and kid's footwear were down against last year, but women's footwear was in positive territory and one of the few highlights for the retail sector - it ranked second after food performance. Sandals sold well in clearance events, with some strong interest in dressy styles. The squeeze on discretionary spending continued to favour value ranges, though premium designer ranges still gave gains for some.
Department stores suffered another difficult month but accessories sales held up and clothing and footwear also showed some growth, though this was often discount-driven.
British Retail Consortium director general Stephen Robertson said: "The negative result confirms fears May's modest like-for-like sales growth was a start-of-summer blip. While total retail sales grew in June, that was by less than half last month's figure."
Robertson added: "Retailers are doing all they can to reassure customers, offering some of the strongest discounts and promotions in decades and keeping a lid on inflation. Surely Government should also be helping hard-pressed customers by not piling on new tax burdens and resisting its instinct for costly new business regulation which ultimately pushes up prices."