BDO's monthly High Street Sales Tracker has reported a 0.9 per cent drop in year-on-year sales for May.
The return of a majority government following the UK election failed to boost consumer confidence, with sales of fashion (down 1.5 per cent YOY) and lifestyle goods (down 0.4 per cent YOY) hit particularly hard in May.
Despite many retailers reporting a decline in footfall, discounting levels were low until the end of the month, when a burst of 'payday' discounting helped claw back some of the losses.
The only sector to show any annual gain was homewares (up 2.5 per cent).
"The uncertainty around the election outcome lasted right up until the exit polls, but we didn't see much evidence of pent up consumer demand once the results were declared," said Sophie Bevan, head of retail and wholesale at BDO.
"With decreasing footfalls, the retail environment remains particularly challenging and retailers will have to continue to focus on all aspects including customer service and getting their products right to see growth this summer, whilst also focusing on their own operating models to protect margins."