The denial of compassion is big business for this government. Under the coming austerity package, which includes a de facto large tax break for bankers, single mothers will be punished more than any other group in society, save those with severe disabilities. Roll that sentence around your mouth and see how bitter it tastes.

This month, expected plans by the Tories to charge separating couples to use the Child Support Agency - essentially a divorce tax for parents - have hit the news. Put this in the context of tax credits and housing benefit cuts that will force many single mothers out of their homes and leave hundreds of thousands more in penury, the removal of legal aid services that allow women to leave abusive husbands without threatening their children's safety, and cuts to front-line public services that will leave more than a million women jobless, and it is hard not to see the scheme as an attack on women dressed up in the bad, Thatcherite drag of think-of-the-children-ism.

What the coalition has just done has made it all but illegal for women earning much under £25,000 a year to leave their husbands. Why? Because it wilfully misunderstands the purpose of the welfare state. In The Pinch, written at the height of Tory propagandising against single and working mothers, David Willetts, who is now a cabinet minister, laments: "A welfare system that was originally designed to compensate men for loss of earnings is slowly and messily redesigned to compensate women for the loss of men."

This is untrue. The welfare state was brokered at a time of high employment when many women were raising children alone because of wartime bereavement. It was there to protect women, working unpaid, from destitution, and was later expanded to allow women with children the option of independence from men. That painfully won independence has just been kneecapped.

Think of the children

The line we are usually spun is that marriage is good for kids, but anyone who grew up with parents guilt-tripped into staying together "for the sake of the children" will understand why decades of research has failed to prove any causative, rather than correlative, link between parents staying married and children growing up happy. The notion that marriage, which only ceased to be understood as a deal to protect property within the past century, magically creates loving relationships through the power of a legally binding document is just propaganda.

Furthermore, it's quite possible that couples forced to stick together because of the financial threat of this new divorce tax might not go on to create a happy little house on the prairie together.

None of this matters to the coalition. The real reason behind the government's crusade to "recognise marriage in the tax system" is breathtakingly cynical: it's about saving money. Persuading poor people to stay married eases the strain on housing stocks and provides a modesty slip for rising inequality; rich couples can still divorce as they please.

This financial intimidation of women with families has nothing to do with the welfare of children and less still to do with "family values". It is a simple cash-grab, dressed up in the language of moral manipulation. This intimate micromanagement of the personal relationships of the poor is a shameless about-face for a party that accused Labour of instituting a nanny state.

The sheer hypocrisy of withdrawing welfare only to shrink the state small enough to fit into people's bedrooms, and the cruelty of playing on women's guilty fear of being bad parents in order to force them to swallow Thatcherite benefit cuts have nothing to do with child welfare.

It's emotional terrorism, and any government should be above it.