Photo: © 2010 AAP/DEAN LEWINS

Under the Coalition scheme, a tax on Australia's biggest companies would pay for mums or dads to stay at home on full pay to raise their newborn for its first six months.

The full details of the $2.7 billion scheme are still to be announced, but it appears at first glance to trump Labor's soon-to-be-implemented $260 million, 18 weeks parental leave.

Abbott is hoping it will help him cut through with female voters where his tips on housework, advice for the bedroom and swimsuit photo ops have so-far failed.

"What's brought [about my change of heart is a] deeper understanding of the practical difficulties of women who are trying to juggle families and careers," he told the ABC 's Lateline program.

"Why shouldn't paid parental leave be as much a part of working as is holiday pay, as is sick pay and as are retirement benefits?"

But big business is far from impressed with the Liberals' largesse.

"The fact is big business is already doing the heavy lifting on paid parental leave,'' Business Council of Australia spokesman Scott Thompson told the Herald Sun.

"Most BCA members already have fully paid parental leave arrangements in place averaging six to seven weeks."