Opposition Leader Tony Abbott will today announce his paid parental leave policy will take effect from mid-2015 if the Coalition wins the election.

Mr Abbott's policy would give new mothers their full replacement salary for 26 weeks, capped at a total benefit of $75,000.

He has previously said that it will be paid for by a 1.5 per cent levy on big business, although it is unclear whether this will cover the full cost of the policy or whether further savings measures are needed.

According to the Coalition, a woman earning $65,000 a year would be about $21,000 better off under its scheme compared with Labor's, and far better off in retirement because its policy includes superannuation.

The scheme would be one of the most generous parental leave schemes in the world.

Labor's scheme, introduced in January 2011, pays a baby's primary carer the minimum wage for 18 weeks.

The Coalition has already announced it plans to cut the company tax rate by 1.5 per cent from July 1, 2015, which may help offset the parental leave levy imposed on big businesses.

Mr Abbott is expected to release further details today.