Gordon Brown should learn a lesson from the Wimbledon tennis championships and do more to close the gender pay gap, a campaign group has said.
Wimbledon has introduced equal money for women from this year
The Fawcett Society's comments come as Wimbledon, which starts later on Monday, introduces equal prize money for men and women for the first time.
As Mr Brown prepares to become prime minister, the body wants all firms to be forced to pay women an equal wage.
"The ball's in his court," said the pressure group.
The Fawcett Society says that women working full time still earn on average 17% less per hour than men, while women working part time earn 38% less.
It adds that this disparity remains despite more than 30 years of equal pay legislation.
"It's time for Gordon Brown to give all women a sporting chance and finally end the pay gap," said Fawcett Society leader, Dr Katherine Rake.
The organisation wants the government to force firms to carry out pay audits to make sure their female employees are not being underpaid.
It has also pressed Mr Brown to tackle the UK's long hours working culture, which it says limits the ability of women with caring responsibilities to compete on an equal basis with men.