One in five employees have been working for an extra 25 hours a week unpaid during the recession - equivalent to an extra three days of work, new research has revealed.
The 'employee attitudes in the credit crunch' survey of 1,000 employees conducted by HR services provider Ceridian, found that half of employees were working some unpaid overtime.
With half of employees having taken a pay freeze or cut, 56% acknowledged that it would probably be more than a year before their pay improved.
The report said: "With the amount of discretionary overtime and the recognition that it could be a year or more before times improve, it would seem employees have grasped the severity of the situation and are adapting.
"The challenge for HR is to maintain the health, wellness and productivity of the workforce to ensure stress incidents and sickness absence remain in check, at the same time as driving performance through innovative rewards that match the challenging business environment."
But these longer working hours have already led to an increase in workplace stress and have had a negative impact on staff behaviour.
While nearly three quarters of employees felt they would stay with their current employer when the upturn came, of the quarter who said they would leave, 16% cited the behaviour of their line-managers during the recession as a reason to move on and 9% claimed they had been bullied.
Post-recession 69% of employees felt they should be rewarded for their loyalty, with over two thirds of those who said this wanting a financial reward.
But overall, 40% of those surveyed said job security was their number one priority - twice the number who cited a pay rise.
Jeremy Campbell, HR outsourcing director at Ceridian, said: "It seems that employers who can offer security and stability, rather than the possibility of bonuses, will be in the best position to attract and retain key talent when the upturn arrives.
"Opportunities to progress are still key to employee engagement and forward-thinking HR directors recognise this."
Research by the Trades Union Congress found that finance staff and garage workers were the most likely to do unpaid overtime.