Britain’s state pension age may need to rise as high as 75 by 2039 unless the government acts urgently to reverse a “collapsing” birth rate, according to a stark new report from the Centre for Social Justice (CSJ). The warning comes as the UK’s Total Fertility Rate sank to a record low of 1.41 in 2024, well below the 2.1 threshold required to maintain a stable population without relying on migration.
The findings, backed by former Conservative MP Miriam Cates, lay out a troubling demographic trajectory that could reshape the economics of retirement for an entire generation. Children currently in primary school, the report suggests, may ultimately work well into their seventies before qualifying for state support, a prospect the CSJ describes as a “catastrophic failure to support the next generation of families.”
A Shrinking Workforce, a Growing Crisis
At the heart of the report is a stark imbalance between workers and retirees. In the 1970s, four workers supported every pensioner in Britain. That ratio is projected to fall to 3.5 by next year and, according to the CSJ’s analysis, could reach a breaking point of just 2:1 within the coming generations. To preserve the current balance of roughly 280 pensioners per 1,000 working-age people, the pension age would need to rise dramatically.
The think tank also highlights what it calls a significant “birth gap”: in 2024, more than 830,000 people turned 50 while only 600,000 babies were born. The UK, the report states, would need an additional 250,000 births annually simply to stabilize its population. The Budget watchdog has separately forecast that public debt could soar to 270 percent of GDP by the 2070s, driven by escalating healthcare and pension costs for an ageing population.
“When fewer children are born, fewer workers enter the labour force, and the burden of supporting an ageing population falls on a shrinking number of taxpayers,” said Edward Davies, research director at the CSJ.
Marriage Rates and Pro-Natal Policy
The CSJ identifies falling marriage rates, women having children later in life, and men delaying entry into adulthood as the principal drivers of the fertility decline. Approximately three million women in the UK are currently projected never to have children under existing trends, representing 600,000 fewer births compared to previous generations.
According to the report, immigration has only temporarily masked the effects of this decline, with fewer workers now shouldering greater tax burdens. The CSJ argues that fiscal incentives alone cannot reverse the trend, and that addressing the fall in marriage rates must come first.
To that end, the think tank is urging policymakers to adopt “pro-natal” measures modeled on approaches seen in France and Hungary, including tax relief for families, housing priority for young parents, and policies encouraging earlier transitions into adulthood and employment for young men.
Miriam Cates, who serves as Senior Fellow at the CSJ, said that “modern life is pushing that dream further out of reach” for millions of women who still hope to start a family, calling on politicians to make family formation a national priority rather than an afterthought.
