ONS data shows they are working for free from 1 September, almost three months earlier than Equal Pay Day for all women

Women with children earn £302 less every week than men with children: one-third less per week and almost 20% less per hour, according to analysis based on ONS data.

This means that Mums’ Equal Pay Day falls on 1 September this year, almost three months earlier than Equal Pay Day for all women. From this date, mothers are working for free for the rest of the year compared with fathers.

“The reason the gender pay gap worsens so significantly after having children is because starting a family has a disproportionately negative impact on women’s earnings,” said Joeli Brearley, the founder of Growth Spurt, an online back-to-work scheme for parents.

The analysis has been acknowledged as accurate by the Office for National Statistics. But the picture is really much worse, said Brearley, because it does not account for the many parents who become economically inactive owing to their caring responsibilities.