Sometimes you don't notice a line in the sand until you trip over it. What is most shocking about the outcry over Tesco's "workfare" job advert, which offered the exciting opportunity to stack shelves for "Jobseeker's Allowance plus expenses", is that anyone was shocked.

Workfare of this kind has been part of the plan for years. But something has snapped. Twitter and the Daily Mail, the Scylla and Charybdis of public disapprobation, are foaming with outrage and companies that had signed up to get forced labour on the cheap are jumping ship.

In the middle of the worst economic crisis in living memory, the centre right is on a mission to make pauperisation socially acceptable. Words such as "incentivise" and "encourage" are used to describe the policy of forcing people to choose between starvation and accepting poverty wages. A welfare system intended to ensure that no child should go hungry, in a country where the average pay of investment bankers at one company is £236,000, is undermined by attacks on "scrounging" and "entitlement".

Yes, many in Britain have become dependent on welfare. The reason for this is not that we have suddenly become a nation that prefers to put our collective feet up in a pair of looted trainers and watch The Xtra Factor than go out and do a day's work. The reason is that a day's work no longer pays the rent.

Nor has it done for some time. Due to the rising cost of property, the lack of social housing and the end of rent controls, hundreds of thousands of families rely on welfare to keep a roof over their heads: more housing benefit recipients are in work than are unemployed. For years, stagnating wages were topped up by credit but now the credit is gone.

So the narrative must be rewritten. The poor, the sick and the disabled must be blamed for their circumstances. I am currently visiting the US, where destitution has been socially acceptable for some time. Bill Clinton's and Newt Gingrich's 1996 reforms refashioned welfare from a system of social support to a way of providing business with warm, docile bodies on the cheap by shovelling people into low-waged jobs. Everyone I meet here dreads unemployment, because there is no safety net. This British government, like the one before it, appears to believe that the US model offers a solution to the economic crisis.

Suits them

The trouble is that workfare doesn't work. It doesn't work in the US, where poverty is at its highest level for two decades, and it won't work in Britain. For the stuffed suits in the world's financial centres, making workers choose between low-paid labour and abject poverty makes perfect sense. It seems to have come as an enormous surprise, however, that not everybody else is OK with this plan. Tesco has said that its advert was a mistake. Too right it was - it was a mistake to think that the British public was ready to accept workfare.

Keeping people happy with low pay, long hours and crippling debt has always required careful PR work, but there are few ways to spin mass pauperisation successfully without the promise of a better tomorrow.