MPs have accused the Government of failing to take action to cut the gender pay gap, warning that barriers to women getting a well-paid job will continue.
The Women and Equalities Select Committee said the Government was "complicit" in a system that was undermining productivity and maintaining the difference between the pay of men and women.
The 19.2% difference in pay for full- and part-time workers had remained the same for four years, with women aged between 50 and 57 facing a differential of 27%, said the report.
The MPs said more should be done to help women return to work, adding that not enough attention had been paid to the low wages of women in sectors such as retail, care and cleaning.
The Government was urged to offer three months' paid leave for fathers, and said all jobs should be flexible.
Conservative MP Maria Miller, a former minister, who chairs the committee, said: "The gender pay gap is holding back women and that isn't going to change unless the Government changes its policies now.
"The pay gap represents a massive loss to the UK's economy and we must address it in the face of an ageing workforce, a skills crisis and the need for a more competitive economy.
"If the Government is serious about long-term, sustainable growth it must invest in tackling the root causes of the gender pay gap. Adopting our recommendations would be a significant step towards achieving the goal of eliminating the gender pay gap within a generation."
The committee said attitudes to work and caring were changing among employers, but it added that part-time work was still underpaid and limited career progression.
Ministers were not taking action to ensure that flexible working was offered to all employees, especially those in low-paid sectors, said the report.
Sarah Jackson, chief executive of the charity Working Families, said: "The gender pay gap remains a stubborn reality. We need the radical solutions the committee proposes if we're going to change things for the next generation of mothers and fathers.
"The 'motherhood penalty' is a price that women continue to pay at work and at home. The answer lies with fathers. A decent period of paid paternity leave would allow more fathers to care for their young children and push this out of the domain of 'women's work' for good."
TUC general secretary Frances O'Grady said: "David Cameron promised pay equality within a generation, but this won't happen by tinkering around the edges. We need a proper shake-up of the current order.
"If we don't tackle problems like occupational segregation, the motherhood pay penalty and barriers to more equal parenting, the gender pay gap will take decades to close."
Sam Smethers, chief executive of the Fawcett Society said: "The committee is rightly focusing on the unequal impact of caring roles as a major cause of the gender pay gap.
"We particularly welcome the recommendation that all jobs should be flexible by default but we think that this should be backed up with additional regulation as a requirement on employers."
Kamaljeet Jandu, national officer of the GMB union said: "Women members of the GMB, working in lower paid, insecure sectors are looking for real change to their pay.
"We have had equal pay legislation since the 70s, but women are still paid less than men.
"Great strides have been made to reduce the gender pay gap but to fully eliminate it the time has come for the Government to compel employers to have mandatory equal pay audits and address the findings."