One in five people fear they will have to work until their 70s before being able to retire, a new study has revealed.
Some believe they will never be able to stop working, amid worries about long-term savings and pensions.
A survey of almost 2,000 workers by Willis Towers Watson found that people under the age of 40 were more likely to be resigning themselves to staying in jobs until they were 70.
Fiona Matthews, of Willis Towers Watson, said: "These figures put into sharp focus the worries that British workers have about their long-term savings and financial security in old age.
"This is already causing stress and having a negative impact on their health. Although employment levels are good and wages are rising, many employees are worried about long-term financial stability.
"They are anticipating longer careers and, for many, working longer is the only way to achieve security in retirement."
A Department for Work and Pensions spokesman said: "We know that many people are not saving enough to maintain their standard of living in retirement. That's precisely why we introduced wide ranging reforms to make pension saving easier, clearer and more sustainable.
"From safeguarding the triple lock and encouraging millions more to save through automatic enrolment, we are committed to helping people have a financially secure retirement."