Opposition Leader Tony Abbott has never believed in paid parental leave and doesn't believe in it now, Small Business Minister Craig Emerson says.
Mr Abbott's scheme of six months paid leave for workers, capped at $150,000, was "political posturing", he said.
"He's never believed in paid parental leave, he doesn't believe in it now," Dr Emerson told Sky News on Sunday.
The small business minister painted a gloomy picture for the pathway through the Senate of Labor's planned scheme of 18 weeks paid leave at the minimum wage.
He predicted the opposition would move amendments to the scheme, which "presumably" won't be accepted by the government.
"If they block it then Tony Abbott is the Tony Abbott of 2002, he said this'd happen over his dead body," Dr Emerson said.
"Surely Tony Abbott would not be so opportunistic as to deny women the opportunity of paid parental leave."
Dr Emerson also used the opportunity to accuse the coalition of obstructionism in the Senate.
"What I've never seen before is this pattern of general obstructionism from the coalition government, where we now have 51 pieces of legislation backed up in the Senate," he said.
"This is just an attempt to block everything that Labor is trying to get through in the Senate."
Meanwhile, the opposition says it's been forced into funding its parental leave scheme with a tax levy because Labor has spent the budget surplus.
"We would prefer that a universal paid parental scheme be paid out of the federal budget surplus," Deputy Opposition Leader Julie Bishop told the Nine Network on Sunday.
"But there is no surplus, Labor has spent the surplus, they've driven us into deficit and they've driven up a massive debt."
So the coalition has come up with what previous coalition governments had done in the past.
"And that is impose what we hope will be a temporary levy," Ms Bishop said.
Temporary levies existed under the Howard government, she said, including a superannuation surcharge levy which was in place until 2005.
As it presently stands, the opposition's policy would tax businesses to fund six months paid parental leave for workers, capped at $150,000.
Ms Bishop denied the opposition leader had about turned on the issue.
"I think Tony Abbott has been very consistent on this for some time," she said.
Under the government scheme - which is planned to start in January 2011 - mums or dads will be given 18-weeks off at the minimum wage.