The Government is a Decade Behind the Data

The Office for National Statistics has published its latest Families and Households bulletin. Married couples now make up 65.3% of UK families, down from 66.6% a decade ago. Family law firms have pounced: the law, they say, must catch up with the cohabiting families displacing marriage. The Ministry of Justice is about to open a spring 2026 consultation on new statutory financial rights for cohabiting couples on relationship breakdown.

Go back to the data and the case falls apart.

When couples actually raise dependent children, what do they choose? The 2025 ONS UK workbook is unambiguous. Of 6.57 million UK couples raising dependent children, 5.29 million are married or civil-partnered. That is 80.5%. Only 1.28 million are cohabiting, or 19.5%. Four out of every five couples raising a dependent child have made a legal commitment, married or civil-partnered, not merely cohabiting.

The “decline of marriage” the reformers invoke has been slowing for thirty years. Between 1996 and 2005, the married share fell by 5.87 percentage points. Between 2005 and 2015, by 3.85. Between 2015 and 2025, by just 1.28. Each decade the rate of decline has slowed sharply. Anyone can check every number: download the ONS 2025 UK workbook and open Table 1, where row 13 is the married-couple family total and row 36 is all families, by year back to 1996.

Cohabitation growth has also slowed. Between 1996 and 2015 the number of opposite-sex cohabiting couple families more than doubled. Yet the overall cohabiting share of UK families has barely moved since 2015, from 17.0% to 17.6%, a change the ONS itself describes as “not statistically significant”. And the estimate for same-sex cohabiting couples raising dependent children is categorised by the ONS itself as unreliable for practical purposes.

The Government is preparing to reshape family law on a narrative the data has already outgrown.

This is not an adult rights argument. It is a children’s wellbeing argument. When marriage was redefined over a decade ago, the injury was not to couples whose rights civil partnership had already secured. It was to the settled principle, carried in UK law for centuries, that a child’s best starting point is a mother and a father committed to each other for life. That is what the consultation should be tested against. That is what the ONS data, properly read, still supports. And that is what marriage delivers.

C4M will make these points publicly, and respond formally to the consultation when it opens. We will ensure that you have a simple guide so you can do the same!