Middle Class Problems: Is it ethical to scoop up the choicest supermarket markdowns?

Night has fallen, and in the aisles at Waitrose, the bar-scanners are roaming, seeking out sell-by dates, printing reduced prices.

There are bargains galore: Essential chicory is down, as is vegetable stew mix (70p), kale (25p), brie (£5 a kilo), tomatoes (50p), granary sticks and an organic wholemeal loaf (25p), grapes (£1.59) and daffs (79p). Here, for a fiver, with the help of a few lentils, is a substantial meal for four, complete with leftovers, tomorrow's packed lunch and a table centrepiece.

The solitary bankers and power couples in pursuit of these bargains are on substantial incomes, but everyone feels the pinch in their own way. A quid saved on guacamole offsets the rising cost of Crozes-Hermitage 2012. And no one wants to see food wasted: better cheaply in your fridge than in landfill, murdering polar-bear cubs.

No intelligent shopper observes sell-by dates anyway: how can narcissus in bud be off? Does the cheese smell funny? It's MEANT to smell funny! Smelling funny is what you pay extra for. It's £11.95 for a small wheel of Mont d'Or at Paxton and Whitfield, for heaven's sake. Sell-by dates are history. There's only one rule: bread is brown, vegetables green – only avoid if the colours appear the other way round.

But is it ethical to scoop up the choicest markdowns? There's no obvious sign of a struggling single mother or homeless army veteran around, but your conscience is pricking. So you blow the savings and a bit more on beans and pasta, drop them in the food-bank collection, and scuttle home.