According to the Hay Group UK, organisations will face a talent exodus of disengaged employees, overstretched and under-rewarded in the recession.
The study, The Loyalty Deficit, of 1000 front-line employees also reveals how some employers have broken an unwritten ‘contract' with staff, jeopardising loyalty, commitment and ultimately their firm's ability to rebound out of recession.
Two thirds (65%) of staff are working over and above contracted hours and more than a third (36%) have increased the amount of overtime they put in over the past 12 months. The average amount of unpaid overtime workers are currently clocking up is six hours per week.
But this extra time is being put in willingly as workers pull together. The majority (85%) of those working unpaid overtime are committed to helping their organisation survive the recession, while 84% say that people in their team are willing to go beyond their normal responsibilities to help each other out.
But half (50%) of these employees warn that this level of work is unsustainable.
Seven out of 10 (70%), claim that overwork is having a negative impact on their relationships and family life, while a similar proportion (76%) complain it is affecting their general health and wellbeing.
Despite this ‘Dunkirk spirit' among front-line workers, employee engagement levels stand significantly below normal levels - 59% against normative levels of 72%, while more than a third of employees (36%) are ‘unhappy' in their current role.
And almost (30%) rate their organisation as a worse place to work compared with 12 months ago.
Russell Hobby, associate director at Hay Group, said: "Walking around the office, leaders may feel the warm glow of a ‘Dunkirk spirit' among teams battling through the recession together.
"However, managers should beware of superficial engagement, where levels of effort and staff retention are artificially inflated by redundancy fears and a soft employment market, rather than genuine loyalty to the firm.
"Those companies solely focused on the bottom line during the recession could easily fail to notice the debt they have built up with employees for their loyalty during tough times. They risk falling behind those few organisations that have bucked the trend and successfully kept engagement high."
More than half of employees surveyed (53%) describe working under a ‘climate of fear' for their jobs. One third (33%) of workers are actively looking for a new job, and nearly half (47%) plan to leave in the next two years.
Of those planning to stay in their role for at least another year, over four fifths (88%) attribute this to a lack of vacancies elsewhere, while 92% fear the risk of starting a new job in the current economic climate. However, approaching half (41%) say they are more likely to leave their employer when there is an improvement in the economic environment.
Just under two fifths (39%) of workers feel their employers have broken an unspoken contract of loyalty with their staff over the past 12 months.
Nearly half (46%) no longer have faith in their employer, while approaching half (45%) are now less proud to work for their organisation compared with a year ago; 46% are less inclined to recommend it as a place to work to friends or family.
Consequently, the vast majority (91%) of workers claim they ‘work to live' rather than ‘live to work'; 16% of them say this has changed in the past 12 months.
Staff cannot maintain the 'Dunkirk spirit' and will leave as soon as the economy improves

UK employees have stretched themselves 'to the limit' to get their organisations through the recession, but this has taken a toll on employee engagement levels, new research reveals.