The irony didn't escape me, when, on Boxing Day, I found myself taking calls from the media, explaining why shop workers shouldn't have to work on Boxing Day. That was four years ago, when I worked for Usdaw, the shop workers' union.

Fast forward to 2012, and Sunday trading was relaxed temporarily for the Olympic and Paralympic Games. The Games are over but the debate rages on. Should shops continue to open all hours, including for longer on Sundays?

The argument seems to focus on the fact that we're an increasingly secular country, most of whom don't attend church on a Sunday, so why not deregulate Sunday trading? I'll tell you why not.

The reason Christians argue for a day off is because it's good for people to have a rest, not for some abstract or particularly religious reason. Jesus annoyed the authorities of his day by being anti-legalistic, picking corn on the Sabbath (which was considered 'work') and claiming that, "The Sabbath was made for man, not man for the Sabbath." A day off is to make life easier, not harder.

While our lives may be a little easier if we can pop to the shops for milk, think how much less easy it is for shop workers, for whom it's just like any other day. There need to be safeguards in place so that they can rest too.

In law, shop workers can ask not to work on Sundays, but increased Sunday opening hours mean that many workers report feeling pressurised to work whether they want to or not. They might want to show that they are committed to the job, make sure they get a promotion or perhaps just don't want to let down their colleagues, who also have to muck in with shifts.

They can take off days during the week instead, but it's not the same. In a way it doesn't really matter which day people have off, so long as most people are off at the same time. It allows people to see their families/friends and enjoy a day that is different to all the rest.

Doctors, police etc. have to work Sunday shifts, but why add to that unnecessarily?

The lovely irony is that businesses themselves are more productive if they allow their employees rest, as W. K. Kellogg discovered in 1935. In a counter-intuitive move, he cut his staff's working day by two whole hours, whilst keeping their pay the same. Both morale and productivity rose. Why?

A change really is as good as a rest. A day off can allow a shift of perspectives – from needing to produce and acquire to simply enjoying the release of just being. This freedom tends to make folk more, not less, productive.

Philosopher and rabbi, A J Heschel, elucidated this beautifully:

"There is a realm of time where the goal is not to have but to be, not to own but to give, not to control but to share, not to subdue but to be in accord. Life goes wrong when the control of space, the acquisition of things of space, becomes our sole concern."