In total, the basket of 42 groceries would have averaged around £11 more at Sainsbury’s Local and £10 more at Tesco Express for loyalty scheme members, compared to their price

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

A 500g bag of own-label fusilli was 31 per cent or 20p cheaper at a larger Sainsbury's supermarket at 65p instead of 85p. A medium white Hovis loaf cost 12 per cent more at both Sainsbury's Local and Tesco Express, and 14 per cent more at Morrisons Daily.