Just over one million people aged over 65 were in work or seeking employment between May and July this year, up from 706,000 during the same period in 2008.

Almost a third (9.1 million) of the UK workforce is now over the age of 50 – an increase of 12% over the last five years, the report by the insurer Partnership found.

It said that while the end to the default retirement age has contributed to the increase, 71% of 50-65 year olds work to supplement their income in retirement.

The report found that a third of 50-65 year olds had put aside savings and investments to fill this gap but up to 39% will rely on continued paid employment of some sort.

Meanwhile, some 21% of those surveyed intend to delay their retirement and 18% will look to set up a small business or take on part-time work when they finish their current role.

More than half of over-50s said that people should be able to work for as long as they are able, while 48% felt there should be more opportunities for part-time work in retirement.

However, 31% said over-65s should retire so younger people could be employed. 24% suggested the Government should pay older people to undertake community service.

Andrew Megson, managing director of retirement at Partnership said: “With almost three quarters of 50 – 65 year olds believing that they will need to supplement their pension income, it is vitally important that they make the most of the savings pot that they do have. Not only do people need to shop around to ascertain what deals are available but they also need to consider whether their health or lifestyle might have an impact on their annuity income.”