Mothers are paid an average of 3 per cent less for every child they have compared to their female counterparts who do not have children, according to a French study, which also shows that fathers suffer no penalty at all.

The study conducted by the Université Paris-Saclay, based on 16 years of data from the French private sector, found that after having a child, women are often allocated to assignments considered to be “less risky”, so are less likely to receive bonuses and are more likely to become trapped in low-wage trajectories.

“Gender inequalities persist within households, in terms of the share of domestic work or bargaining power, but they also persist within firms,” said Lionel Wilner, the author of the study.

“The gender pay gap, occupational gender segregation and the glass ceiling are the most striking examples – but an obvious example of gender inequality is related to childbirth,” he said.

“The motherhood penalty accounts for noticeable hourly wage differences following childbirth.”

He describes the wage gap as both unfair and inefficient and calls for “public intervention” in the form of “campaigns against discrimination” and the provision of on-the-job childcare.

He said that a paternity leave of the same duration as maternity leave would also be a step towards closing this gender gap.

The gender pay gap has become subject to fierce debate in the UK in recent months with pressure groups and campaigners regularly criticising the Government for not doing enough to combat discrimination.

As of Thursday last week, companies in the UK employing more than 250 people have 12 months to meet a deadline to publish their gender pay gap figures, but critics have said that the reporting won’t be granular enough to facilitate real change.

According to the Fawcett Society, one of the UK’s largest charities promoting women’s rights, the current overall gender gap for full-time workers is 13.9 per cent.

The Society also says that women are frequently being paid less than men in the equivalent role, despite that being illegal.

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Commenting on the Université Paris-Saclay study, Kate Headley, director of human resources at Clear Company, an online consultancy which promotes diversity in the workplace, said that “organisations need to create an inclusive culture to which equality and diversity are fundamental if they truly want to address gender inequality in the workplace.”