Currently, trading laws are biased in a number of ways.
1) Only certain businesses are restricted (garages, pubs etc. can open all day Sunday)
2) It removes the rights of workers to maximize their earnings (students etc.)
3) It removes the rights of the consumer to manage their own time and choose when they wish to visit supermarkets etc.
4) It removes the rights of businesses to provide services and gain competative advantages
5) It is prejudiced against people with certain working patterns and lifestyles.
Currently, as the law stands, you can buy alcohol and cigerettes from a pub but you cannot buy bread or tomatoes from a supermarket.
If someone, for whatever reasons (religious or traditional) wishes to abstain from certain activities on any particular day of the week or year then that is there individual choice and it should not be inflicted on the rest of the nation who may not agree.