Female managers effectively work for free for an hour and 40 minutes every day, a new study has found - with women being paid around a fifth lower than their male counterparts.
Experts called the findings "unacceptable".
Researchers found women in full-time managerial jobs earn an average of 22 per cent less than men in the same roles - the equivalent of going unpaid for 100 minutes a day, or 57 days a year.
The study, carried out by the Chartered Management Institute (CMI) and wage analysts XpertHR, found that the gender pay gap for professional roles averaged some £8,500 a year - rising to almost £15,000 for senior staff.
And the gap increases as women get older, starting at just a six per cent difference for women aged between 26 and 35, and rising to 38 per cent for the over-60s.
The research also showed that while women outnumbered men in junior management roles, there were fewer than one in four serving on company boards - just short of the 25 per cent target set by Lord Davies.
CMI chief executive Ann Francke said it was "unacceptable" that the gender pay gap still persisted 45 years after the first equal pay legislation was passed.
The government's Women's Minister Caroline Dinenage said plans to force all companies with 250 or more employees to publish their gender pay gap would "ensure the economy fully benefits from women's talents and fairly rewards them".
"I would encourage all companies to have their say on the consultation to help us eliminate the gender pay gap in a generation," she added.The TUC union's general secretary, Frances O'Grady, welcomed the move to improve transparency, but said it did not "go far enough".
ITV News spoke to entrepreneur Emma Sinclair and the head of Wimbledon High School Jane Lunnon to get their thoughts.?