On the flipside have a fair few women friends on facebook who work in retail who are moaning about it today - their husband/partner (typically) works 9-5 mon-fri and they work i.e. atleast one of the days on the weekend often both depending on shifts so it erodes not insignificantly into the time they do get to do stuff as a family plus inevitably if it does become normal they'll be asked to increase their availability to cover the extra hours as well.
I'm not exactly inspired by the reasoning of the person behind it either heh:
"Anna Soubry is on a mission to cheer up Sundays and her solution is shopping."
"It was the most "miserable" day of the week and as far as she is concerned it was a myth that families came together on the day of rest."
Reads a bit delusional to me regardless of the merits or otherwise of extended Sunday opening.