The proportion of those who work more than forty eight hours a week has increased from one in ten to one in four during the past five years while the average woman's working week is half a day longer.
A survey of 1,666 workers by the Chartered Institute of Personnel and Development (CIPD) showed that men's hours have fallen from 45.5 hours a week five years ago to 44.8 now while the average working week for all workers stands at 39.6 hours, slightly up on figures for 1998.
The working week for women has increased by three and half hours to 33.9, reflecting the growing number of women working as managers or in professional jobs where hours are longer.
According to the CIPD, the figures suggest that the Government‚Äôs campaign on work-life balance has had little or no effect to date.
"The only crumb of comfort for the Government lies in the fact that almost 1 in 4 employees have cut back their hours in the past 5 years, although the biggest single factor behind this reduction is parenthood," the report says.
Underlining the negative effects of working long hours, most long hours workers surveyed report some kind of negative effect on job performance.
One in four said that long hours got in the way of their relationship with their partner or spouse and the same number reported damaging effects on their mental health in terms of stress or depression. More than a quarter also say that long hours has affected their sex lives and the relationship with their children
Most people who worked long hours were likely to go to work even if they were unwell, and two-thirds had gone to the office on public holidays in the past year. Half of those putting in long hours would even choose work ahead of a personal commitment.
But putting in excessive hours affected workers' performance, with three-quarters admitting they took longer to complete a task and made mistakes.
But despite this, the survey found no difference in the satisfaction levels at or outside work between those who work more than 48 hours and those who work less.
Mike Emmott, head of employee relations at CIPD, said the survey also found little support for ending the UK's opt-out from a European Working Time Directive aimed at limiting the working week to 48 hours.
"Half of those who work long hours say they do so entirely as a result of their own choice," he said. "More than half are either managers or professionals who should be well placed to exercise informed choices about their hours.
"Some employers are asking staff to sign an opt-out clause simply in order to take the issue of long hours off the table and avoid the possible need for record keeping, even though employees rarely or never work more than 48 hours for long periods. It would therefore be disastrous to remove the opt-out at a stroke."
And on the broader points raised in the report, Emmott said that the upwards trend in women's working hours is not necessarily a bad thing.
"The increasing number of female long hours workers is not surprising given that a higher proportion of them are managers and professionals, who tend to work the longest hours.
"As the service sector continues to grow and male-dominated sectors such as manufacturing, mining and agriculture continue to decline, this trend looks set to continue."
Nevertheless, he added, "the new right to request flexible working will undoubtedly help employees to achieve the balance between home and work that best suits their circumstances and needs."