The latest report from the Advertising Standards Authority suggests the multiples are increasingly scouring through the small print of competitors' ads to trip them up on price claims. Sainsbury was caught out this month when rivals Tesco and Asda quibbled over the precise implications of its We won't be beaten on price' slogan. The ASA dismissed claims the statement implied Sainsbury's offered prices guaranteed to be lower than competitors. But it upheld Asda's complaint about a specific ad claiming Sainsbury's beat rivals on price for Persil and Comfort. The products were found to be cheaper at Asda when the ad first came out. A spokesman from the ASA said the industry was now so competitive that the multiples watched each other's campaigns like hawks. But the number of complaints upheld against supermarkets has actually decreased in recent years after retailers were issued with guidance to help them interpret advertising codes. Nevertheless, this is now the fourth complaint upheld against Sainsbury in the last 12 months. Tesco follows closely behind with three complaints upheld, Asda with two and Somerfield with one. There were no substantiated complaints against Safeway or Morrisons. {{NEWS }}