INDEPENDENT shopkeepers have launched a stinging attack on competition regulators this weekend, accusing them of failing to do enough research on the buying power of Britain’s four biggest supermarkets.

James Lowman, chief executive of the Association of Convenience Stores (ACS), which represents 33,000 small shops, claimed that the Competition Commision had carried out only “pretty cursory work” on buyer power, and had not gone deep enough in its latest probe into the country’s grocery market.

The ACS will publish its own study next week. The research, shown exclusively to The Sunday Times, gives the strongest indication yet that the buying power of the big four supermarkets – Tesco, Asda, Wm Morrison and J Sains-bury – is distorting competition in the British grocery market.

The study investigated more than 300 different product lines. It demonstrates that 10% of products on a supermarket shelf are cheaper than the price a wholesaler which supplies independent stores can pay to its own suppliers.

The research also shows that almost three-quarters of items in supermarkets are sold at a price that suggests they obtain lower buying rates than the independent sector.

Lowman said: “This study shows that in one in ten cases, a small shop cannot buy products from their wholesaler cheaper than they could off the shelf in a supermarket.

“This is the single-most compelling proof that there is a severe competition problem in the market and shows how important it is that the Competition Commission goes further in their probe of the relationship between supermarkets and their suppliers.”

The study directly counters the view expressed by the commission in its recently published “emerging thinking” document that no systematic differential exists between supermarket buying and the rest of the market.

Lowman added: “Supermarkets obtain preferential buying terms that are generated not from their volume and efficiencies but from the ability to dominate their suppliers.

“This market is not working effectively. If the Competition Commission does not act, the situation will continue to worsen, small competitors will struggle to remain competitive and consumers will lose the choice and diversity that is vital to a strong grocery market and to communities throughout the country.” Lowman claimed that he was “astonished” when the Competition Commission report suggested there was no “systematic differential” in favour of supermarkets.

“This was a reflection of the failings in their early evidence-gathering rather than a reflection of what is actually happening in the grocery market,” he said.

The ACS wants the Competition Commission to use its powers to compel the big supermarket chains to reveal at what prices they are buying goods from their suppliers.

The relationship between buyers and suppliers strikes at the very heart of the commission’s inquiry.

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