Food retailers are shielding customers from the full impact of soaring commodity prices, according to figures produced by the British Retail Consor- tium (BRC).

The Shop Price Index, developed by the Consortium and administered by marketing information company AC Nielsen, showed that fresh food prices increased by 6.4% in May compared with this time last year, a rise from 4.5% in April. But the BRC noted that, according to the Office for National Statistics (ONS), increases in the price of petroleum products faced by retailers amounted to 25.4% and therefore "consumers have experienced a comparatively small increase in the price of fresh foods".

BRC director general Stephen Robertson said: "Intense pressure from rising costs has pushed up the shop price of food, but it is clear retailers are continuing to shield customers from the full impact."

Meanwhile annual inflation for ambient food was 5.4% in May, compared to 5% in April. The BRC report said ambient food faced the same inflationary pressures as fresh foods, with the additional impact of rises in bread and cereal prices, which it added were "mainly the effects of shortages in soft commodities such as rice and grains".

The problems have been exacerbated, according to the BRC, by price controls and export restrictions imposed by up to 30 commodity-producing countries.