Tens of thousands of working mothers in the UK were refused furlough requests from managers that would allow them to look after their children and home school them during coronavirus lockdowns.
The extent of the crisis was revealed in a survey of 50,000 women and prompted calls for extra legal rights for all parents.
A Trades Union Congress study found that 70 per cent of requests for furlough were refused, 25 per cent of women fear they will lose their jobs, and 90 per cent of mothers say their mental health has been harmed.
The TUC wants to introduce new laws that give parents extra rights.
Analysis by the UK's Office for National Statistics found that during the first national lockdown, parents could catch up only by working late at night or early in the mornings.
“Just like in the first lockdown, mums are shouldering the majority of child care. Tens of thousands of mums have told us they are despairing. It’s neither possible nor sustainable for them to work as normal, while looking after their children and supervising schoolwork,” said TUC general secretary Frances O’Grady.
“Making staff take weeks of unpaid leave isn’t the answer,” she said. “Bosses must do the right thing and offer maximum flexibility to mums and dads who can’t work because of child care.
“And as a last resort, parents must have a temporary right to be furloughed when their boss will not agree.”
Parents should have a temporary legal right to access the furlough scheme – a government-funded project to help people not working because of the pandemic – for existing childcare commitments or if they have to shield family members, the TUC said.
Parents should also be given 10 extra days of holiday for carer leave days, the organisation said.
The pandemic has exposed the root cause of the problem: "We don't have a parental leave system that is fit for purpose," the TUC wrote in its report Working Mums: Paying the Price.
One mother told the labour union organisation: “I asked for furlough and they told me to try and make other arrangements. My only options have been to use annual leave or take unpaid leave, both of which I don't want and can't afford to do.”
One campaign group for working mothers facing the prospect of losing their jobs said a survey of 2,000 women on its site found that 20 per cent had left or been forced out of their jobs since schools switched to remote learning.