The federal opposition is facing questions over its policy stances on parental leave and workplace reform, as Labor puts the finishing touches to the May budget.

Liberal MP Alex Hawke has broken ranks to query Opposition Leader Tony Abbott's generous plan for a paid parental leave scheme funded by a 1.5 per cent levy on more than 3000 big companies.

Mr Hawke says the plan is "an albatross" around the party's neck, it isn't good economic policy and he advocates keeping the existing scheme.

He's hinted many of his coalition colleagues also oppose Mr Abbott's plan.

"The feedback from business groups, from women in the community and from colleagues is that now would be a very good time to revisit this policy with a view to scrapping it before the next election so we can go to the election without this albatross around the neck of the party," Mr Hawke told ABC radio on Monday.

The MP for the north western Sydney seat of Mitchell will expand on the issue in an article to be published next month by the Institute of Public Affairs.

Families Minister Jenny Macklin says the opposition is "laying the groundwork to dump" the plan, which Mr Abbott has described as a "signature policy".

"Tony Abbott's colleagues are openly admitting that his plan is unfair," Ms Macklin said in a statement.

"They know it rewards high-flying bank executives and lawyers."

Ms Macklin has also warned Mr Abbott's commitment to dump Labor's school kids annual bonus if he wins government in September would hurt lower paid mums.

Opposition frontbencher Malcolm Turnbull says the coalition is committed to the parental leave scheme, even if there are differing views within the party.

Fellow frontbencher Christopher Pyne says the policy is "pro-family, pro-business and pro-employee".

And he says the Liberal party has room for people with the "intellect and capacity to mount public policy arguments".

Under the coalition parental leave plan, new mothers would get six months' replacement salary of up to $75,000 - paid for by the levy on big business.

Mr Abbott last week supported Labor's planned rise in the Medicare levy from 1.5 per cent to two per cent to help pay for a national disability care scheme, despite initial internal party concerns.

Meanwhile, in a "soft launch" of its workplace relations policy, the coalition will brief business representatives on the broad outline in Canberra on Monday.

It appears changes to unfair dismissal laws won't be in the policy, after Mr Abbott told News Limited it wasn't something business chiefs were demanding.

But he said the laws would be kept "under review".

Workplace Relations Minister Bill Shorten said the coalition's industrial policy "remains in witness protection".

"Mr Abbott has revealed that whatever business asks for, they shall receive under a Liberal government," he said.

Federal cabinet will meet in Canberra on Monday to finalise plans ahead of the May 14 budget.