Attempts to make Tony Abbott's paid parental leave scheme conditional on mothers returning to work may not be enough to win over dissident coalition senators.
Treasurer Joe Hockey has revealed that there would be a "mutual obligation" element to the PPL scheme which would allow mothers to stay at home with their babies for six months at full pay, capped at payouts of $75,000.
The Commission of Audit is believed to have been critical of the PPL policy in its yet-to-be-released report, echoing business community concerns that the policy would not increase workforce participation.
Despite the criticism, the Prime Minister has made it clear he will not accept any retreat on his "signature" policy that is part-funded by a 1.5 per cent levy on big companies.
Mr Hockey said the mutual obligation principle would be applied to the $5.5 billion-a-year PPL scheme, as it would to other Government programs.
"Well, essentially they have to return to work," Mr Hockey told Sydney radio this week.
"When you see the legislation it will be clear, there will be a form of obligation."
The work test for the existing parental leave pay - 18 weeks of the minimum wage - is not prospective and instead is payable if the mother worked at least one day a week in 10 of the 13 months before the birth or adoption.
Mr Abbott's PPL policy has its enemies within coalition ranks.
Many Liberals believe the policy's extravagance runs counter to the broader Government narrative about an end to the "Age of Entitlement", while Nationals believe the policy discriminates against stay-at-home mums.
Coalition senators have told The Weekend West there are talks behind the scenes on what it would take to get 38 votes to kill off the PPL legislation when the new Senate sits after July 1.
The Government leadership may seek to cut a deal with the Greens to pass the legislation but if five or six coalition senators cross the floor, it may be enough for the Bill to be defeated.
One coalition figure said not only was the PPL policy too generous, it would also mostly benefit highly paid women who needed little incentive to return to work.