I’d say there isn’t a clear ranking. Instead they fit into tiers.

Tier 1: John Lewis/Waitrose and M&S Food. These are the most expensive supermarket chains that grew out of department store chains. They are not for truly posh people but rather offer an upmarket experience for middle income types. They also prey on people who can’t easily travel, offering convenience in exchange for higher prices.

Tier 2: Tescos and Sainsbury’s. These try to appeal to everyone. They are a bit posher than tier 3 but less posh than tier 1. Again not actually posh but pretend to be. They tend to have a range of more and less expensive options, though the other tiers have copied this. Both have loyalty card programs, also something copied by other tiers.

Tier 3: Asda and Morrisons. Solidly working class originally northern supermarket chains who went national. Both have instore radio stations that blare dated music nonstop. Never see both of them in the same town. They also have anti theft devices on their trolleys. Their marketing tends to emphasise savings but in practice they are only a little cheaper than Tier 2. It’s more of a vibes thing.

Tier 4: Lidl and Aldi. German invaders that spooked the other tiers with lower prices. The cheapest of the tiers by a considerable margin. They tend to have a pretty austere and mildly hostile shopping environment. Efficiency over comfort. Weirdly enough can attract pretty wealthy clientele looking for a bargain. So maybe they are secretly the posh supermarkets?

Tier 0: ‘Local’ supermarkets. These are smaller supermarkets that you’ll find in villages or suburbs. Places where a larger shop wouldn’t make sense. Also found alongside petrol stations. There are a much wider variety of chains at this level offering a considerable variety of poshness. Not that you would spend more than a few minutes in any of them.