TUC chief Brendan Barber has warned employers there is "no room for complacency" after research showed that one in four employees was dissatisfied at work.
Speaking exclusively to Personnel Today, Barber said that while UK workplaces were not a "seething mass of discontent", swathes of employees endured long hours, stress, low pack and lack of career progression.
The TUC's What do workers want study polled 2,857 employees and found a third did not feel engaged by their employer and less than half thought that their organisation deserved their loyalty.
"It is part of the human condition to find something to moan about at work, even if it's only the canteen menu," Barber said. "It does not mean that there is room for complacency."
He added that UK workplaces could be divided into three basic types.
At the bottom, approximately one in five of the workforce had a grim time at work, according to Barber. "If not actually exploited, then they have high pressure but dull jobs that give no chance to progress." At the top end, a larger group have great jobs that involve them and use their full potential, he added.
"But in the middle, the great mass have jobs that are basically OK, but do not really get the best out of people and are, therefore, not as fulfilling or as productive as they could be," Barber said. "Muddling through has always been the British disease, and it is as true in the workplace as anywhere."
The top attribute that people looked for in a job was fair pay (98%), but only two-thirds of workers said that they got this, according to the survey.
The biggest gap between aspiration and reality was 'opportunities for promotion and advancement' - three-quarters said this was important, but only a third felt they had the opportunities.