What a gift for the Coalition.

Just when Iain Duncan Smith was showing the strain of having to pretend he could live on £53 a week, along comes Mick Philpott, arsonist, philanderer, dirty slob, child killer and perfect cartoon cut-out of a "benefits scrounger".

Most newspapers, including The Herald, reported the conviction of Philpott, his wife Mairead and their accomplice Paul Mosley for the manslaughter of six of their children in a fire in Derby last year as the tragedy it truly was: a revenge plot by a violent, brazen, manipulative man against his former lover that went disastrously wrong. No prizes for guessing which newspapers deemed the vile vengeance of Victory Road to be a parable for our age. Only readers of the paper's Scottish edition were spared the Daily Mail's banner headline: "Vile product of welfare UK". (They must have had the champagne out at the Department for Work and Pensions.)

Inside AN Wilson declares that the sad saga demonstrates "the pervasiveness of evil born out of welfare dependency". The eccentric novelist was sure William Beveridge and Clement Attlee would be birling in their graves at the notion of Mick and "his house, his drugs, his 17 children paid for by a benefits system meant to be a safety net for the truly needy". Reaching a crescendo of apoplectic rhetoric, he declares that "versions of the Philpott family can be found in any town in Britain. Whole blocks of flats, whole tenement buildings are filled with drug-taking benefit fraudsters, scroungers and people on the make". He concludes that a decent job would have redeemed mad Mick.

The facts don't quite fit. For a start Philpott wasn't claiming benefits but merely channelled the child benefit and tax credits his wife and lover collected on the back of their part-time cleaning jobs into his own bank account, along with fees for magazine articles about his notorious domestic arrangements. This is the story of a degenerate control freak and misogynist who treated his women like slaves and cynically used his children as pawns in his power games.

Of course, for the peddlers of welfare mythology, the facts are immaterial. The Coalition's dog whistles on this subject have been so effective that on average people think 27% of the welfare budget is claimed fraudulently, even though the Government's own estimate is 0.7%. In recent years references to benefit cheats have morphed into vague talk of "scroungers", who are perceived as making insufficient effort to get work or more hours. It emerged yesterday the Government's next target is to cut tax credits, used to boost the earnings of the low-paid, if the one million who depend on them are deemed to be doing too little to boost their earnings. Even LibDems who should know better, like Jo Swinson, meekly mouth the Coalition line on issues like the bedroom tax.

Another popular theme to emerge recently is to blame the high benefits bills on large families. Families like the Philpotts and Heather Frost from Gloucestershire, with her 11 kids and a horse. The Philpotts will be quoted as an example of why a benefits cap is necessary. Yet only 1% of households living on benefits have more than five children and fewer than 200 in the entire UK have 10 or more. These children did not ask to be born. Why should they be singled out for harsh treatment?

George Osborne's oft-quoted £100,000 a year in housing benefit turns out to apply to just five big families, who didn't get to spend it, as it went straight to their landlords. Meanwhile, the stigma that has been created around social security puts off those in genuine need from applying.

Mick Philpott tells us as much about scroungers as Fred West tells us about builders, or Lord Lucan about aristocrats. There are wider lessons to be learned from this tragedy. There are lessons for the social services, who should have known Mick Philpott's violent past and read the danger signs. And there are lessons for a generation that turn cartoon villains like this vile man and the characters from The Scheme into celebrities by gawping at them on television and devouring their stories in newspapers and magazines.