The government could be forced to award rebates to tens of thousands of self-employed women if a case accusing it of discriminating against those who have taken maternity leave is successful. About 75,000 women who took maternity leave between 2016 and 2019 lost out on earnings because payments from the self-employed income support scheme (SEISS) – introduced alongside the furlough scheme last year – are worked out based on average profits. The payments – which are calculated by taking into account 80% of self-employed profits, averaged out between 2016 to 2019 – do not exempt periods when self-employed women were not earning because they were on maternity leave, or take into account statutory maternity payments. The charity Pregnant Then Screwed (PTS) is bringing a judicial review for indirect sexual discrimination on Thursday, supported by Doughty Street Chambers and law firm Leigh Day. When asked about the issue in parliament, Rishi Sunak said self-employed people had “ups and downs” in their earnings “for all sorts of reasons … whether through maternity, ill health or others’’. PTS founder and CEO Joeli Brearley said: “Giving birth and caring for the next generation, particularly in a baby’s first year of life, is work. It is mentally and physically exhausting work. “For maternity leave to be dismissed as the same as being sick or taking a sabbatical is not only insulting, but it sends out a very dangerous message about how this government views mothers and the integral role we play in a well-functioning society.” Brearley said SEISS calculations breached the anti-discrimination provisions of the Human Rights Act and the requirement in the Equality Act to consider the position of women who did not work for reasons relating to pregnancy or maternity. “This court case is about defending women’s rights and showing the government that they cannot ride roughshod over the Equality act,” she said. Cheryl Liversuch, a self-employed fitness instructor, had her third child in 2018 and went back to full-time work just before the coronavirus pandemic started – her grant was about a third what she would normally earn. She said her partner, who is also self-employed, had received a full grant calculated on his full earnings. “His payments weren’t reduced at all, but obviously he also became a parent – it takes two to tango, but it is only the woman that is penalised for having a family,” she said. Laura, a single parent who did not want to give her surname, said her work as a cake maker had dried up, but because she had a child in May 2017 her SEISS payments were minimal and did not include the maternity allowance she was paid by the government. “So they are paying me maternity pay to cover my income, but not counting it as my income. It doesn’t make any sense,” she said. A Treasury spokesperson said SEISS was “one of the most generous” schemes of its type in the world, claiming that calculating the grant based on average profits over three years better reflected people’s incomes. The spokesperson said: “We understand the challenges for new parents who are self-employed – and even if a new parent did not submit their tax return for 2018-19, they may still be eligible and able to claim for a grant using their self-assessment returns from previous years.”