I'm a retail worker and I and everyone I know thinks this is a terrible idea!
We don't get any extra pay for weekends, Sunday working isn't optional, we already get a raw deal with bank holidays, Christmas etc. Most large supermarkets are already open from 8am on Monday morning until 10pm on Saturday night - I find it difficult to believe that people can't get their shopping done during those hours.
It won't just be supermarkets, all retailers will be affected. Me and my DP can only afford to run 1 car so if we're both at work on a Sunday or bank holiday one of us has to pay £20 for a taxi because public transport still runs Sunday/bank holiday hours.
We only get 1 day off together at Christmas and haven't had a bank holiday together in years.
I know people will say that we should do other jobs if we don't like it, but many people I know chose a career in retail before the days of Sunday opening, extended trading etc.
Please think about it -do you really need a new pair of shoes / tv / sofa at 10pm on a Sunday?