On the go: The UK population is growing older, Office for National Statistics figures have shown, with potentially big repercussions retirement patterns.

By 2050, one in four people in the UK will be 65 or over up from today’s one in five with an additional 8.2 million pensioners.

The greying of the population is despite recent youthful immigration to the UK boosting the numbers of residents to 66.4 million according to the ONS data released on Friday.

Sarah Coates, centre for ageing and demography at the ONS, said: “The structure of the UK’s population is changing: people living longer and having fewer children means the age structure is shifting towards later ages. The ways in which people live are also changing with cohabiting families the fastest-growing family type and more young adults living with their parents.”

One major effect of the shift to longer lives is that people will also have to work longer, with workers making a more gradual retreat from the workplace.  

Nathan Long, senior analyst at Hargreaves Lansdown, said: “The retire-as-you-go generation blend their balance between work and life to suit their needs.”

However, he added: “The next 10 years will see a generation of people born too late to benefit from generous final salary pensions but too early to get the full benefit of auto-enrolment, coming to retirement with less stashed in their pensions and the inevitable consequence is they’ll need to work longer.”