As many as five million people aged 50 and over will continue working after they turn 65 – and 300,000 of them are not planning to ever retire.
And if half of those currently working and turning 65 this year do not retire they will contribute around £7bn to the economy annually.
Some £5.4bn would come from part-time workers while full-time staff would create another £1.6bn.
Almost half of Britons want to continue working in some form after reaching retirement, research by pensions firm Retirement Advantage found.
Of these people, 43 per cent plan to switch to part-time work, while six per cent do not think they will ever stop full-time work – up from four per cent in 2016.
Andrew Tully of Retirement Advantage said: “The idea of cliff-edge retirements are put firmly in the past as half the over 50s have no plans to fully retire when the time comes.
“This generation will continue to make a significant contribution to the economy in the future and employers will need to consider how best to adapt to this changing employment landscape.
“People clearly enjoy the social aspects as well as financial benefits of work, but there is a cautionary tale in these statistics.
“A significant minority do not plan to ever stop working, with the number increasing over the last year.
“This may be perfectly reasonable for some people but it may also reflect a growing pressure to work to be able to pay the bills.”
Mr Tully also pointed out that plans to work beyond retirement have an impact on pension savings which could see workers hit with a tax bill.
More than one in three workers using new freedoms to access cash from their retirement fund continue to pay into a pension.
Worryingly, 67 per cent are unaware of the Money Purchase Annual Allowance which severely restricts the amount you can continue to pay into a pension once benefits have been taken.
Mr Tully added: “People gradually easing into retirement by working part-time may also have taken some of their pension benefits and could find themselves falling foul of the tax rules.”
Contrary to popular perceptions that financial worries are what drive older people to stay in their jobs, when asked why they are considering working past state pension age the most popular reason for 54 per cent was that they simply like working.
The next most common reasons include work providing a sense of purpose (53 per cent) and to avoid boredom (52 per cent).
Forty two per cent of the over 50s said they wanted to ease into retirement gradually.
Needing the extra money comes in fifth at 41 per cent, with women more likely to be motivated by this than men.