See article here.
I can see there problem with bare feet, but wouldn't a notice stating it was at your own risk cover that one?
Are they going to start defining what nightwear is? If I wear it in bed at night does it become nightwear? So those old sports trousers that I wore in bed during pregnancy are forever banned from seeing the light of day?
I don't know if this Tesco is 24hrs, but if you have to do an emergency middle of the night shop, getting dressed isn't high on my list of priorities.
But then you are talking to the woman who deliberately has outside shoes for slippers, so that if I forget to change them, no one notices.