As retirement ages get pushed back, new research suggests UK workers are far from confident that they will be able to do their job by the age of 70.

Longevity think tank Phoenix Insights found that while more than three quarters (78%) of workers were confident they could do their job at 60, the number falls to half (49%) by 70.

That could be a problem, the think tank said, as widespread under saving means many may need to work beyond the age of 70 to support their living standards in retirement.

Its modelling suggests around 17 million UK adults are not on track for the retirement income they expect or need, with the saving crisis expected to reach boiling point for new retirees in the 2040s.

Remaining in work, on reduced hours or full time, has the double effect of reducing the years to fund in retirement alongside the ability to continue to build up pension savings, Phoenix Insights said.

The biggest concerns to remaining in work are physical and mental health, motivation and age discrimination.

The research found that only around one in three 65 year olds were classified as fully retired, compared to the three quarters recorded 30 years ago.

A quarter of all 60-65 year olds live in poverty and people out of work aged 60-65 were twice as likely to be in poverty as those in work.

Patrick Thomson, head of research analysis and policy at Phoenix Insights said: “How people enter, stay and leave work has transformed in recent decades. The average retirement age has increased by around five years since the 1990s and more people choose a gradual transition from work rather than having a hard stop.

“In the future, it’s possible average retirement ages will rise further alongside the state pension age rises as people want to continue working longer or feel they need to for financial reasons. In the next five years most defined contribution pension savers will enter retirement with savings below expectations or below an adequate level, and this will worsen to a peak in the early 2040s.”

He said that huge numbers of people drop out of work before state pension age and face barriers to re-entering. “Without better support for this group to remain in work, an increasing state pension age and under saving creates a perfect storm for worsening later life poverty.”