There's a version of the denomination to which I belong called the Seventh Day Baptists. They are quite small and not very well known, but they have one distinctive tenet: they believe in worship on the Jewish Sabbath, Saturday, rather than on the Christian one, Sunday. It hardly seems like the sort of thing to drive a wedge between Christians, but that's Baptists for you.

I wish I belonged to them, because it would make what I have to say about Sunday trading just a bit more credible.

The Chancellor, George Osborne, has announced an 'Enterprise bill' for the autumn which will include provisions for handing over decisions about Sunday trading rules to local mayors and councils. It's out for 'consultation', but we can expect a massive lobby by big business in its favour.

I'm against it, and I hope many, many other Christians raise their voices against it too.

The trouble is that it's easy for its supporters to say that Christians just want to defend the 'sanctity of the Lord's Day' when most people don't go to church and have a deep-rooted objection to being bossed around by people who do.

Hence my attraction to the Seventh Day Baptists. Because there's nothing doctrinally significant about a particular day. The point is that our society still has one day that's different – when more couples can have more time together, more families can have a day that's theirs, instead of one of them having to work, and when it's acknowledged in law that profit isn't everything and that we don't live by bread alone.

At the moment, large stores can only open for six hours on Sundays. It's not much of a concession, but it's one that those of us who campaigned against the liberalisation of the Sunday trading laws in 1994 were glad to get. It means that small family-run shops have some protection against the march of the megastores; they don't have to open every day to keep competitive. It means that for those who have to work, days can be shorter. It means that communities in busy shopping districts have time to recover and to breathe before they're hit by waves of consumers again.

If the Chancellor's proposals go through, all that will change. It won't happen overnight – local resistance will be strong in some areas – but the pressure from big business will be immense.

But while the hired pollsters will talk about how much people want it and the hired economists will talk about fiscal uplift, the voice of those who talk about the cost of deregulating Sundays needs to be heard too.

CARE CEO Nola Leach says: "Family life should not be sacrificed on the altar of profit. Britain can only win the global race if we pace ourselves and that's why the principal of time off in common, where families can spend time together, is so vital.

"Extending trading hours on a Sunday in our view is an extraordinarily short-sighted policy that will place even greater strains on our society's fragile social fabric.

"Family breakdown already costs the Exchequer in the region of £46 billion a year, £34billion more than the savings the Chancellor wants to make by cutting the welfare budget. We are deeply concerned about the consequences these proposals could have on the social environment of British society."

She goes on to warn about the way "quality of life and personal wellbeing" will suffer if these proposals go through.

Intuitively, that sounds right. But there's also evidence to back it up. A 2007 Australian study conducted by The Relationships Foundation, An Unexpected Tragedy, looked at how changing patterns of work had affected family life. It compares working patterns from 30 years ago, when most people worked on weekdays between 8am and 6pm, with the situation today – long hours, a strong tendency for work on weeknights and weekends, and a relatively large proportion of the working population employed on a casual basis.

It says that "these long and atypical working patterns are associated with dysfunctional family environments", including bad health, strained family relationships, parenting "marked by anger, inconsistency and ineffectiveness" and reduced child wellbeing.

Is that really what we want in the UK too, where family life is hard enough anyway?

The government backed up its proposals with research from the New West End Company, which said extending Sunday trading by two hours in London alone would generate 3,000 jobs and more than £200 million a year in extra income. I think we should take that with the proverbial pinch of salt. But even if it were true, some things can be too dearly bought. We aren't just producers and consumers. There's more to life than that.

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