Those were the findings from new research from employee benefits consultancy Portus.

Its study showed 66% of the UK working population expect to have to keep going till past 65 with 11% believing they will continue working past 76.

The main reason for carrying on – cited by 74% - is that they though they would lack enough money to live on. Some 13% believed it would be because they will have to provide financial support to their children, and 4% said they would be funding grandchildren.

Portus’s research shows that 50% of those people aged 65-plus who are still working are doing so because they do not have enough money to live on while 22% are working to help children and 6% are still in jobs to help fund grandchildren.

Recruitment consultants surveyed by Portus believe the rise of the older worker is unstoppable – with in one in five recruitment consultants saying 20% of the UK workforce will be 65-plus within five years.

Around 10.3% of the UK workforce is aged 65 and over, but 63% of consultants surveyed said they expected this to rise to 15% or over by 2020.

Around two out of five (42%) of workers believed they would have adequate income during their retirement. However just 7% were very confident while one in ten (10%) were ‘very unconfident’ they would.

Despite the retirement gloom just over one in four of those who expect to work beyond 65 (26%) say they would do this because they enjoyed working and wouldn’t want to get bored if they stop.

Steve Watson, Portus Consulting commercial director, said: “The demographics of the UK workforce are changing rapidly and this has huge implications for employers in terms of the range of employee benefits they offer.

“For example, an older workforce will want greater access to advice or guidance on how to use their pension savings whilst still at work, and it can also have huge implications for the provision of medical and critical insurance cover, for example.”