Families Minister Jenny Macklin claims charities and universities will face a hit to their coffers if the coalition persists with its generous paid parental leave scheme in government.
The coalition plans to impose a 1.5 per cent levy on more than 3000 companies to help fund its $5.5 billion a year scheme.
But the business levy does not qualify for franking credits so shareholders will lose tax breaks on their dividend payments from listed companies, many of which will have to pay the impost.
Ms Macklin says charities, universities and foundations will be among the losers, citing tax office statistics that so-called imputation credits are a growing source of revenue for many of those organisations.
"They, too, will be contributing to Tony Abbott's unfair and expensive paid parental leave scheme," she told ABC Radio on Friday.
"There's a lot of people who are very concerned about it."
Under the coalition plan working women will receive six months' parental leave on full pay, capped at $75,000, plus superannuation. It will apply for babies born from July 1, 2015.
Earlier this week, it emerged self-funded retirees and mum and dad investors could be $1.6 billion worse off because the business levy does not qualify for franking credits.
Ms Macklin dismissed comments by prominent feminist icon Eva Cox that Mr Abbott's scheme was better for women.
The Labor government has an 18-week scheme, paid as a welfare entitlement at the national minium wage - $622 a week pre-tax.
"I am a feminist and I'm very proud of our scheme," Ms Macklin said.
