Waitrose has won the Top Store award this week, breaking a Morrisons winning streak that had seen the Bradford-based company coming first in five of the previous six weeks. Our shopper at the John Lewis-owned store in Bury St Edmunds, Suffolk, found all the products she needed in a thoughtfully laid out and spacious environment. And staff were "exceptionally helpful".

The Asda store on Coventry Road, Birmingham was cluttered with trolleys and boxes when our shopper visited. When she made it through to the register, she met a rather unsociable checkout assistant who avoided eye contact, mumbled and offered no help with her shopping bags.

In Cambuslang, Lanarkshire, our mystery shopper visited a Morrisons that was clean and

well-merchandised and staffed by helpful shop assistants. Also in Scotland, the Somerfield store on East Main Street in Broxburn, West Lothian, was in very good shape when our shopper turned up.

It was a disappointing day at the Sainsbury's in Southend, Essex: the store was dirty and the aisles were cluttered. The cashier failed to charge our mystery shopper for the parsnips in her bag.

Our mystery shopper at the Tesco store in Amersham, Buckinghamshire, said store assistants picking products for home delivery obstructed the shelves and aisles, which made her shopping trip difficult.