In this third part in our series on how the UK has changed in the past 25 years, we turn to demographics, immigration, social attitudes and LGBTQ lives.

Athina Vlachantoni, professor of gerontology and social policy, University of Southampton

Jane Falkingham, professor of demography and international social policy, University of Southampton

Maria Evandrou, professor of gerontology, University of Southampton

The UK population grew in size from just under 59 million in 2000 to 69.5 million in 2025, and is now projected to reach 71 million by 2034. Contrast this with sharp population declines in eastern and southern Europe that prompted a European parliament resolution in 2021 on reversing demographic trends in EU regions.

The UK’s population growth reflects recent trends in the three drivers of population change – fertility, mortality and migration – which have implications for future generations and the country as a whole.

The UK population is ageing

The 2001 UK census showed that around 16% of the population (9.5 million people) were 65 and over, while just under 2% or 1.1 million were 85 and over. By 2025 the Office for National Statistics estimated that the over-65s and over-85s accounted for 20% and 3% of the population respectively.

More people living longer is both a success for the human race and a challenge for policymakers and societies. A woman and man aged 65 today are expected to live on average for another 23 and 20 years respectively, with important consequences for how long pensions and other savings need to last.

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The House of Lords Economic Affairs Committee found in 2025 that the UK is “strikingly unprepared for an ageing society”, as a result of increasing costs and a shrinking tax base. Incidentally, despite women living longer than men, a greater proportion of their lives are expected to be spent in poor health.

The UK is becoming more ethnically diverse

In 2001, 11.8% of the population was from minority ethnic communities, whereas by the 2021 census it was 18%. Although white British people still constitute the largest part of the population (over 74%), their proportion has decreased. There have been slow increases in people from Asian ethnic communities (9.3%), white “other” (6.2%) and black groups (4%), reflecting patterns of both past and more recent migration.

Migrants contribute to the growth of the population and – importantly – the labour market, driving economic growth. As the Windrush generation ages, we are seeing more diversity in our population across all age groups.

Families are getting smaller

Women are having fewer children. The total fertility rate stood at 1.7 children per woman in 2000, and after a revival in the mid-2010s, reached 1.4 in 2024, the lowest since records began.

The average age of women at first birth in England stood at 31 in 2024 compared to 29 in 2000. This is due to a combination of factors, including increased participation in higher education, delayed marriage and partnership formation, and younger generations’ desire to establish a career, get on the property ladder and achieve financial stability before starting a family.

The Resolution Foundation has warned that “the recent fertility decline appears to be driven, in part, by financial constraints facing young non-graduates, rather than a shift in what people actually want”.

As a result of these three demographic shifts – the ageing population, increased ethnic diversity and smaller families – the shape of households is changing. Married couples made up 66% of families in 2025, compared to 70% in 2001. The proportion is decreasing as a result of other family types becoming more prevalent, including lone-parent, cohabiting couple and civil-partner couple families.

The proportion of single-person households has remained relatively stable over the last 25 years (around 30% of all households). However, the composition has changed, with the proportion of 65 and overs in this category increasing from about 46% in 2001 to nearly 50% today.

Demographic changes are taking place at the same time as, and partly because of, the broader socioeconomic changes which have led to greater inequalities for people across the life course. For example, research by the Resolution Foundation has shown that the bottom half of the income distribution is older and more ethnically mixed than 30 years ago, and more likely to be childless and single than before.

Rob McNeil, deputy director, Migration Observatory, University of Oxford

There are a lot more foreign-born people in the UK in 2026 than there were in 2001. The exact number is uncertain because the UK’s migration data has been sketchy since the 2021 census, with some fairly wild fluctuations during this period, as you can see in the graph below. But in 2001 the UK’s total foreign-born population was 4.9 million, and by 2024 it was estimated at 13.1 million.

UK net migration and immigration (1991-present)

When Tony Blair’s New Labour had stormed........

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