@ Jennyema & Andy M: My apologies for leading you astray. I posted the two links because they were convenient and because they show the many difference between English and US cows; the former do not have a tenderloin,for example, and because I didn't realize that the technical use of Chuck on the English cow, could be used to imply that the young woman at Sainsbury's was ignorant of her trade or dishonest (trying to palm off surplus stock).
My BGD (beloved granddaughter) is, at 18, already an accomplished cook and we went meat shopping together in Asian markets as recently as Thanksgiving. She is also becoming a good researcher, so yesterday, I sent her an Email package on this topic, including the thread, a 1970's English recipe that called for chuck steak and a reference to braising steak, and asked her to come up with a good short argument on whether or not the young woman at Sainsbury's was ignorant/badly trained, or whether she had no way of knowing what a chuck steak was from her training. This morning I got three links. She had googled Sainsbury's main site and entered "braising steak" in the search box, which gave 20 hits, and "chuck" which gave zero hits.
What a nice use of Occam's razor! I have a tendency to think that the more references I have the better and try to overcome the opposition by weight of numbers, but this easily accessed reference cuts to the chase and. short of writing to the head of Sainsbury's butcher school, answers the question, which is not "does anyone in England know what chuck is?" but "should a Sainsbury trained butcher know what chuck is?".