This week the chancellor announced that from 2025 parents will be offered free childcare for their children as young as 9 months old. Whereas parents will now be able to send their tiny children to be looked after by strangers outside of the family, there is no equivalent provision to support those who prefer to care for their toddlers at home or with grandparents.

Some mothers – and let’s face it this is about mothers – will undoubtedly relish the opportunity to return to work. Parenting small children can be a mind-numbingly thankless task. As a father of six children, now all young adults, I loved them with all my heart and did my fair share of playing on the floor and changing nappies. But I am very glad that I didn’t carry the main burden of childcare that my wife did. Adults need mental stimulation and challenge. Work can provide that outlet and my wife is now well-established once again as a social entrepreneur in the voluntary sector.

But it is also the case that children benefit most from care at home. If you doubt that, there’s an entire body of literature that talks about the importance of attachment. Let’s not over-exaggerate the risk though. For most children, any negative effects of childcare are small and modest. Nonetheless, from the point of view of children, policy points in the wrong direction. The apparent benefit of an early return to work for parents has trumped what’s generally best for most young children. This is pressure, not choice.

Yet while I don’t feel especially strongly about the new childcare policy, the fact that we have it reflects on our wider family policy priorities that are deeply warped and ultimately anti-family.

With noble exceptions, few people debate why we treat people differently for tax and benefits. If you pay money to the state, you’re treated as an individual. But if you receive money from the state, you’re treated as a household. This might maximise treasury profits. But it’s the worst possible arrangement for families.

Let’s start with tax. If one parent earns all of the money so that the other parent can stay at home and look after the children, they will pay more tax than if they earn the same money between them. As a family, you probably don’t care who earns the money. But if only one of you earns all of it, you pay more tax because the tax system treats people as individuals. ‘Specialisation’ of family roles (regardless of who does what) is penalised. The financial incentive is for both parents to work and put the children in childcare.

Most countries in Europe treat the family as a unit and allow income splitting or transfer of allowances (as if both parents were earning the money) which brings the tax bill down and gives genuine choice about childcare. In contrast our tax system is skewed against parental choice and individual enterprise. It encourages parents to take on two modest jobs rather than one good one and penalises those who prefer to specialise their roles as one primary earner and one primary carer.

Former tax inspectors Don Draper and Leonard Beighton at the charity CARE have been lone voices on this subject for years. More recently the Tory MP Miriam Cates has bravely taken up the issue. More people need to talk about this anti-family policy.

But for me, the truly appalling and unjust anti-family policy is how we do welfare. Unlike tax, universal credit does treat the family as a unit and calculates welfare payments based on household income. This makes some sense in that it would be mad to pay a stay-at-home mother welfare if she is married to a millionaire. The flip side is that it actively discourages any kind of couple stability. If you’re on low or no income and your partner or spouse moves in with you, their income is added to the household income on which welfare payments are calculated. Young mothers on low income – and it is mostly young mothers – stand to lose part or all their universal credit if they move in with their partner, let alone marry them, God forbid.

I have yet to hear a single politician talk publicly about the ‘couple penalty’. Most don’t even know about it. Young mothers do. My academic predecessor Dr Rita Griffiths wrote a brilliant PhD thesis showing that welfare was ‘strongly influential’ on partnership formation decisions by 51 mothers in the Liverpool area.

I have been writing and talking about the ‘couple penalty’ since 2006 without much effect! In my view this is the single biggest barrier to marriage, and therefore greater relationship certainty and stability, among low income couples. It’s why access to marriage is a social justice issue. Two of our most recent papers at Marriage Foundation show (a) how the marriage gap has built up between rich and poor and (b) how the poorest married parents have much the same stability as the richest of unmarried cohabitees. We should be encouraging marriage, not putting up barriers for the poorest.

So if you’ve read this far, type up a quick email to your MP and ask them why they think we treat people as individuals for tax and households for welfare. Our tax policy penalises families who think the family benefits most if one parent earns and the other cares. And our welfare policy penalises low income couples who want to live together, let alone marry.

This is plain stupid.