. . . takes leave of what little sense it ever had, and requires us to buy our eggs buy weight, rather than by number. How many eggs make a kilo?
Here's the way round it, if it ever happens. Take a plastic fridge box with you to the supermarket. Open 2 cartons of eggs, which will still contain 6,10,12 or 18. Take out an odd number of eggs, say 11, 13 or 17.
Put them carefully into your box. At the check-out say (politely of course) "I need only 17 eggs this week. Will you please weigh them for me." The checkout person will probably refuse, saying, "We sell them only in 6,10,12,18 or whatever." In which case, you say, "Oh! I thought you had to sell them by weight now. Like the onions. Oh well, if you can't weigh them, I'll just leave them with you. But I want my box back, so mind they don't roll on the floor."
Or . . . and this gives the supermarket even more trouble - which is what you're after, because the only way to end this nonsense is to get the supermarkets and the egg distributors SCREAMING at the UK Government to get the nonsense stopped. Open lots and lots of egg cartons. Take random numbers of eggs to the weighing-scales, usually to be found by the vegetable displays. Weigh your eggs. If they don't come to the exact kilo, or whatever "weight" of eggs you want, leave them amongst the tomatoes and onions, go back to where the eggs are and get some more. Eventually a supermarket minimanager will say "Nell Pugh?" (This is under 40's contemporary supermarket English for "Can I help you?") You say "I want a kilo of eggs. But I can't get them to weigh out exactly to a kilo. Er . . sorry about the mess. Hope I haven't broken any. You'll know more about egg weights than I do. Perhaps you could weigh a kilo for me?"
What I mean, folks is . . . if you allow this crap legislation to happen you deserve all you get from the European Parliament and its careerist-cretin Commissioners. (Remember their unbending attitude to bananas?)