Older employees are increasingly working unpaid overtime, entrenching the UK's long hours culture, according to new research.
The TUC said a quarter of a million more workers in their late 50s and early 60s put in unpaid hours last year compared with 2001, taking the total to more than 660,000.
The main reason was that people were working beyond their traditional retirement age because of fears about a loss in income, said the report. In contrast, the proportion of employees in their early 20s working overtime for no extra money has fallen by a third in the last decade, the study found.
The likelihood of unpaid overtime increases the longer someone has been in a job, with teachers, media workers, financial services managers and health and social services staff most likely to work for nothing.
One in five workers puts in an average of more than seven hours of unpaid overtime every week, worth £5,300 each or a record £29 billion to the economy, said the TUC, which published the figures to mark Work Your Proper Hours Day.
TUC general secretary Brendan Barber said: "A lot of older workers are keen to reduce their hours as they approach retirement, but many of them have to top up their contracted hours with extra working time for free.
"Around one in five workers regularly do unpaid overtime but it's becoming the norm in far too many workplaces. Whilst most people have no objection to putting in some extra hours to help their employer through a busy period, an entrenched long hours culture causes stress, health problems and lower morale.
"We're asking employers to support Work Your Proper Hours Day today by encouraging staff to take a proper lunch break and leave work on time. Given that managers themselves tend to do a lot of unpaid hours, taking a few simple steps to address long hours problems will benefit everyone in the workplace."
Work Your Proper Hours Day is the day when the average person who does unpaid overtime finishes the unpaid days they do every year, and starts earning for themselves, said the TUC.
The figures showed that over half teaching staff worked unpaid overtime, putting in an average of 9.6 extra hours a week. University and College Union general secretary Sally Hunt said: "The Government cannot keep expecting more for less from such dedicated people, particularly when their reward is real-terms pay cuts and attacks on their pensions."