UK retail sales volumes dropped 0.8 per cent month-on-month in September, official figures show, reinforcing expectations that gross domestic product growth will have been weak again in the third quarter.

The seasonally-adjusted figures, published yesterday by the Office for National Statistics, reveal a 1.5 per cent month-on-month tumble in non-food sales volumes. This category tends to reflect more discretionary consumer spending, and the drop in sales volumes appears to highlight the pressure on household finances.

The deflator signalled a 3.3 per cent year-on-year rise in shop prices in September - way ahead of nominal pay growth.

The 0.8 per cent tumble in retail sales volumes last month, which followed a downwardly-revised 0.9 per cent rise in August, was much steeper than the 0.1 per cent dip projected by economists. Food sales volumes fell 0.6 per cent month-on-month in September.

The EY ITEM Club think-tank said: “September’s relapse fuels suspicion that August’s marked gain in sales had been buoyed by tourists being encouraged to spend by the weakened pound and by more people staying at home for the summer holidays.

“The disappointing September retail sales data dilutes hopes GDP growth saw any marked improvement in the third quarter. Indeed, GDP growth could very well have been limited to 0.3 per cent for a third successive quarter.”