Britain is a world leader in family break-up. 60% of British children born to unmarried parents living together experience family breakdown before they hit their teens – compared with 15% of children growing up in Belgium and 6% of Spanish children. Even America has better figures. Only Latvia, out of our European neighbours, has a higher proportion of children growing up in single-parent homes.

When ministers recently looked into the drivers of child poverty, they found that growing up in a family that breaks apart doubles the likelihood of a child growing up poor. By the age of five, half of all children in low-income households no longer live with both birth parents, compared with only a sixth in middle to higher-income households.

In the UK, cohabiting parents are 94% more likely than married parents to break up before their children are 12. However, that doesn’t necessarily mean a marriage will solve all of the problems, as the overall divorce rate in the UK is 33%. If you speak to Peters May – specialist divorce & family lawyers in Mayfair, London – they will confirm how “inherently complex” family law is. A messy divorce will not only take time, but also funds, meaning the now separated parents will likely have even less money.

Children caught up in such family breakdowns are overwhelmingly more likely to fail at school, develop an addiction and languish on benefits. As the figures show, family stability is becoming a middle-class preserve.

Family breakdown is not just about children. It plays an under-recognised role in other important areas. We know that prisoners with stable families are much more likely to be rehabilitated and less likely to reoffend than other prisoners. We have known for a long time that the roots of mental health problems are more often than not to be found within the family.

The demand for state-financed care of our elderly beyond the home is driven by families breaking up and being less able or willing to look after older relatives. Later this year we will reach a “tipping point”, where the number of older people needing care will outstrip the number of working-age family members available to meet that demand.

The Relationships Alliance estimates that the total cost of broken relationships to the exchequer exceeds 48bn.

I wonder, if this cost were incurred in any other government area, just what urgent plans to resolve it would be drawn up.

Debt is one of the biggest causes of family breakdown

I applaud the fact that, in many cases, unmarried couples achieve stability in spite of the difficulties they face. Yet the overall figures speak loudly: cohabitation is the fastest-growing family type in the UK; between 1996 and 2012, the proportion of dependent children living in cohabiting families doubled. A fifth of all couples with dependent children are cohabiting, but they account for nearly half of all family breakdowns. And yet, despite public concern, for too long discussion of this subject has been shut down by the thought police of the liberal left. So powerful were their voices in recent years that the last Labour government took out of public documents references to whether someone was married.

Only a few days ago, their erstwhile leader, Harriet Harman, said once again that politicians should be banned from talking about marriage or the damage that family breakdown can cause.

Sadly for years that attitude has prevailed and, as a result, family breakdown, aided by poor government interference, has grown enormously. Genuine concern for the failing strength of family life is not about disapproval, finger-wagging or moralising but about trying to take action to resolve it.

In this I believe Harman and her acolytes are now out of step with the British people. For when the Centre for Social Justice asked young adults about their aspirations for adult life, three-quarters said they wanted to get married.

When we polled more widely, a majority were strongly in favour of governments promoting family, with eight out of 10 telling us they thought family breakdown was a serious problem.

Eighty per cent of parents from the poorest households (those with the highest levels of family breakdown) thought it right for the government to say that stability mattered for children, and more than half of lone mothers also believed it was important for a child to grow up living with both parents.

There are a number of things we can do. There is a body of evidence showing that we can help couples before they reach crisis point through relationship support and counselling. Yet, even with such evidence of how it is possible to arrest family break-up, it is not seen as a priority. The government spends more on fixing church roofs than it does on relationship support.

Debt is one of the biggest causes of family breakdown and yet our celebrity-obsessed culture too often leads to a spending race to mimic the latest celebrity wedding, which few can afford. The average cost of a wedding is more than 20,000. Very few have that amount to spend, leading many couples to borrow to meet the cost and fall into debt before they even start married life.

This government has done more to address family instability than its predecessors, but there is much more that needs to be done. We should look carefully at how to close the “couple penalty”, where couples in receipt of benefits and tax credits can earn more living apart than together. While the introduction of universal credit will help, the penalty for low-income couples is still too high.

Two years ago the “family test” was launched by David Cameron. Every government policy was to be tested for its impact on the family, but after strong internal resistance it has yet to be properly applied.

Unless we recognise how damaging the high level of family break-up is, particularly for those on the lowest incomes, the government’s good and laudable intentions for social reform will struggle to succeed.