Joan Smith: You try working in a cake shop, Mr Cameron...

I've worked in shops. I've bagged doughnuts, stacked shelves and been sacked from a Saturday job in a boutique. What did I learn from this experience? That I'm good at mental arithmetic and hopeless at persuading women to buy clothes that don't suit them. Oh, and that the boredom would have been intolerable without a pay packet at the end of the week.

Years after I'd given up shop work, a legal minimum wage seemed one of the flagship achievements of Tony Blair's government. I felt like flipping two fingers at bosses who whined that they couldn't afford it, as though labour costs came bottom of their priorities.

Then David Cameron's government offered businesses a legal means of getting round the minimum wage. Dozens of high-street names signed up to provide a "work experience" scheme lasting up to eight weeks; they'd have thousands of young unemployed people providing free labour in their stores while the state paid them £53.45 a week in jobseekers' allowance. No one seemed to mind that taxpayers were subsiding profitable companies such as Tesco – pre-tax profit £1.9bn in the six months to August last year – and T K Maxx.

Until a nationwide campaign against "workfare" took off, participating companies were getting up to 30 hours' unpaid work from each individual who took part in the scheme – a weekly saving of more than £180 if they took on an unemployed 21-year-old. Anyone who left after a week risked losing benefits, undermining the Government's claim that the scheme was entirely voluntary. Now, following a blizzard of bad publicity, T K Maxx, Argos, Superdrug, and now Burger King have withdrawn from the scheme. Several charities have suspended their involvement, and Tesco has offered to pay anyone taking part.

The Prime Minister is furious. Last week, he attacked "dangerous" anti-business hysteria and claims about "slave labour", bringing along the Prince of Wales as a fine example of someone on a work experience scheme. Social commentators joined in, accusing opponents of being snobs who find the whole idea of working in a shop demeaning.

It's hard to think of a more bone-headed accusation. It should be levelled at the companies that offer these "jobs", preferring to have their shelves stacked and floors swept by people they're too mean to pay. What dignity can there be in work when the business offering it values it so little? And then there's the knock-on effect: why would a high-street store pay the minimum wage when the company next door is getting free labour, thanks to the Government?

We're seeing a return to the notion of the "deserving poor", those who have to demonstrate that they're worthy of support through displays of meekness and deference. It's an ideology that gets Tory MPs swooning, even though there's little evidence that such schemes work. Cameron told MPs last week that around half the people on work experience are "actually getting work" at the end of it, but the organisation Full Fact looked at the Government's figures and concluded that there did not seem to be an "adequate basis"for the claim.

The Prime Minister may be getting carried away by his own rhetoric, announcing last week that business is "the most powerful force for social progress the world has ever known". There speaks a man who's never worked an eight-hour shift behind the counter in a cake shop.

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