Waitrose boss Steven Esom believes a suggestion by M&S to introduce a measure of the quality of a retailer's offer to the planning process is flawed.

Following M&S's submission to the Competition Commission, in which it called for a "qualitative" approach to planning rather than the simple needs test, Esom said that while quality was vital it was only a part of what stood the likes of Waitrose and M&S apart.

"Making a decision about quality is difficult; it's totally subjective. Quality is too narrow and other elements such as ranges and services should be considered, too. For us, it is all about choice."