Shops of a certain purely arbitrary size are open for fewer hours on a Sunday than on the other six days of the week. There is absolutely no valid reason for this whatever. The whole thing is an absurd mess which, it seems, is soon to become ever so slightly less absurd a mess. What we need is a comprehensive overhaul of ST law, but as is the British way (civil partnerships for example) we'll have an extended period of half-arsed, half-hearted fudge and compromise before common sense finally kicks in.