The case for a permanent suspension of Sunday trading rules was further weakened by figures showing retail sales fell by 0.4% in August, according to retail and wholesale associations.

The latest BRC-KPMG retail sales monitor shows a like-for-like downturn in UK sales despite hot weather and the Olympics.

Stephen Robertson, director general of the British Retail Consortium, said: “There’s no evidence here of any Olympic boost to retail sales overall. Hot weather and the Olympics did help sales of party food and drink but that was more than offset by a really weak performance for non-food goods.”

Association of Convenience Stores (ACS) chief executive James Lowman said the figures demonstrated that the temporary suspension of Sunday trading rules had no impact on sales overall.

“We were already clear that small stores have suffered a loss of sales to big stores as a result of the change to the Sunday trading rules in place throughout August,” he said. “ACS has consistently argued that the temporary suspension of the rules was unnecessary and these figures show that permanent changes are without merit.”

“The public have sent a clear message to the government,” added Federation of Wholesale Distributors chief executive James Bielby. “They don’t want more time in out-of-town retail parks, they want to spend their free time with families and friends within their communities.

“The rise in sales of snacks, drinks and party food during the Olympics demonstrates this. There is no economic or social case for a permanent relaxation of Sunday trading rules – it will damage local shops, and the consumers have shown they don’t want it.”