Women receive lower pay rises than men when they are promoted because of a "sticky floor" syndrome that holds back their careers, research has found.
A report by academics at Essex University says women are just as likely to win promotion as their male counterparts but employers tend to reward them with smaller pay rises and lower grades.
The stark difference in treatment is said to be because bosses believe that men are more likely to be poached by rival firms and are prepared to match the rates of pay offered by other employers. Women are assumed to be "more loyal servants" who are less likely to leave their jobs in response to an offer elsewhere, the study by Professor Alison Booth found.
The tendency to pay men more means that women are more hampered by a "sticky floor" than the so-called "glass ceiling" through which they cannot rise.
The report says: "Men get bigger salary hikes than women as employers match offers of jobs from outside. Women who get a job offer find that the salary paid by their existing employer is not matched.
"This could be because women are assumed to be more loyal servants and less likely to move jobs in response to an offer." Professor Booth, who is based at the Institute for Social and Economic Research at Essex University, says the survey provides further evidence of the pay divide.
A second study by Professor Booth into working practices shows that less than half of all British employers are now in "regular jobs" working a standard 9am to 5pm week. Almost 60 per cent of workers are either in temporary jobs, regularly work away from the office, have a working week of less than 30 hours or more than 48 hours, or work outside conventional "normal" hours.
Professor Booth's research, which was a joint study with Dr Marco Francesconi, underlines how the "long hours culture" has taken hold in the UK with 17 per cent of employers now working more than 48 hours a week. Another 9 per cent work less than 16 hours and 13 per cent work between 16 and 29 hours a week.
* The Ford motor company announced yesterday that its women workers will be given 100 per cent of their basic pay for the full period of their maternity leave – up to 40 weeks.
Unions welcomed the decision, saying Ford's change of practice would set the pace for motor and other industries.
Currently, women in Britain are only entitled to 90 per cent of their basic pay for the first six weeks of maternity leave and then receive a statutory payment of £62.20 a week for the next 12 weeks. Ford,employs 18,700 workers in the UK, about 1,100 of whom are women.