The six hour limit on Sunday trading for large stores is simply red tape. The whole world does not cave in when shops are open for longer hours on a Sunday, as in Scotland. Given that only a minuscule precentage of the population are Sunday church goers, it is religious discrimination to impose Christian views on the rest of the country. No one is forced to go shopping at 6pm on on a Sunday if they choose not to. However, the choice should be there.
It imposes an unnecessary restriction on free trade and serves no purpose.