Shoppers warned to avoid buying from smaller stores Some items are marked up as high as double the price at convenience stores compared

Consumer website Which? conducted research and found that shopping at convenience stores costs consumers more than doing a weekly shop in a larger supermarket.

The biggest different was at Morrisons Daily, where shoppers paid 21 per cent more on average. Which? found that Sainsbury's and Tesco had less variation in prices, but Nectar mem

The biggest different was at Morrisons Daily, where shoppers paid 21 per cent more on average. Which? found that Sainsbury's and Tesco had less variation in prices, but Nectar members could still be paying an average of 14 per cent more at Sainsbury's Local.

An investigation has found that Tesco, Morrisons and Sainsbury's all charged more for a basket of shopping in their smaller local convenience stores.