The news for Sir Stuart Rose, the chief executive of Marks & Spencer, just gets more and more miserable. In a new mystery-shopping survey, Prophet, the brand strategists, found that shoppers put Middle England's once-favourite shop firmly at the bottom of a list of 11 supermarket groups. Based on mystery-shopping research over the past two months and published tomorrow, Prophet's shoppers put Waitrose as the top supermarket in terms of customer expectations. They were asked to grade the shops – Waitrose was 4.5, Asda, 3.3, Aldi made 3.2 but M&S was 2.5, below the expected level of 3. Prophet's Vanessa Cohen said: "The research is not saying that the customer experience at M&S is below average, but that the customer experience is not as good as it should be."