The gap between the pay of men and women widened to almost 19 per cent last year, reversing a 20-year trend, a new study revealed today.

The difference in hourly earnings grew by 0.3 per cent, mainly because of the growth in earnings of the highest-paid male workers.

Women's average hourly wages in 2002 were £10.22 compared with £12.59 for men, the study by pay analysts Incomes Data Services (IDS) showed.

Under this measure the gender pay gap widened from 81.5 per cent in 2001 to 81.2 per cent last year.

The gap had narrowed at a steady pace of about 0.5 per cent per year since the Eighties, IDS reported.

The gap between average weekly wages, including overtime, also grew last year, with full-time women workers earning £383 compared with £514 for men.

Within the bottom 95 per cent of the workforce, women's average hourly pay grew at a faster rate than men's.

Average hourly earnings for women increased by 4.6 per cent last year and by 5.1 per cent for men.

The ten per cent increase in the national minimum wage in October 2001 had been expected to boost the growth in female earnings and to narrow the pay gap, but this was more than offset by the increase in wages for men with highly-paid jobs.

Women remain concentrated in occupations such as retail assistants, cleaners and clerical jobs, while men are more likely to have management jobs, said the report.

The pay gap was widest among company financial managers and treasurers at 40 per cent.

The findings will dismay equal pay campaigners, including unions which have been calling for compulsory audits in companies to make sure women were not being paid less than men.

Julie Mellor, chairwoman of the Equal Opportunities Commission, said: "This analysis should be seen as a call to action on three fronts to end the scandal of unequal pay.

"Firstly, it is essential that employers review their pay system to ensure they are not short-changing women.

"Secondly, we as a society need to reassess the value we place on jobs traditionally done by women.

"How on earth can we justify, for example, the low pay received by people caring for children and older people - surely one of the most valuable roles?

"Thirdly, Britain needs to tackle women's segregation in low-paid work and the barriers that prevent many reaching senior positions."