Women are likely to earn £300,000 less than male colleagues over their lifetimes as the gender pay gap continues to widen, according to analysis.
On average, women in the UK are said to have taken home more than £5,700 less than men in 2015, accounting for a 24% deficit that takes a woman's pay packet well below the national annual average.
Figures show women's wages are growing at a slower rate than those for men, raising concerns that the "stubborn" pay gap is still not shrinking.
The analysis of provisional figures released by the Office for National Statistics comes ahead of International Women's Day on Tuesday, which this year has #PledgeForParity as its theme.
Katy Tanner, director of Robert Half UK, a recruitment consultancy that carried out the research, said: "International Women's Day provides a platform to highlight the importance of rewarding all employees fairly on the basis of their contribution to the organisation, rather than their gender or indeed any other point of difference."
The firm highlighted recent research by the World Economic Forum that predicted full gender parity would not come about until 2133, but warned the latest statistics suggest it could take even longer.
It referred to figures that showed the median gross pay for full-time male employees in the UK last year was £29,934, but for women it was £24,202, a shortfall of £5,732, or 24%.
When the divide is projected over a career of 52 years, the figures tot up to a lifetime's earnings of £1,556,568 for men and £1,258,504 for women - a £298,064 difference.
The research also revealed that gross annual earnings for women grew 1.4% between 2014 and 2015, compared with 1.6% for men.
"Given men have on average higher salaries to begin with, the absolute difference is magnified still further," Robert Half UK said.