The Government has agreed to make changes to proposed paid parental leave legislation but only for parents of premature babies.
The ACT party had also been trying to negotiate changes to the assistance available to parents of multiple birth babies and children with disabilities.
The Government bill, which is due to have its first reading in Parliament, will make some extensions to the existing paid parental leave scheme for casual and seasonal workers.
ACT leader David Seymour said, following talks with Workplace Relations and Safety Minister Michael Woodhouse, parents of pre-term babies would receive additional weekly payments for each week the baby was born before the 37-week gestation period.
He said they agreed parents of multiple birth babies and children with disabilities already received special assistance in the form of home help payments, childcare subsidies and disability allowances.
He said he had not been done over by the National Party over paid parental leave, rather he was just much better informed now about the support available to some families.
At the start of the year, Mr Seymour agreed to oppose the Labour MP Sue Moroney's bill, after the National Party said it would amendments.
Labour MP Sue Moroney's bill wanted to extend paid parental leave from 14 weeks to six months for all parents and she said the proposal on the table now, was a broken promise.
"It's a promise they made David Seymour in order to stop him voting for the measures that I had proposed in February this year so thousands of families are going to be missing out on an entitlement to paid parental leave, just because of National's political game-playing."
However, Mr Seymour said he worked with National in good faith, and was happy with the concessions that have been made.
"No I feel that when the facts change I change my opinion - we've got new facts and we've made better policy as a result."
Mr Woodhouse said support was already in place, for several years, for multiple births and disabled children.
And he said Mr Seymour's vote would have made no difference either way to the success of Sue Moroney's member's bill.
"It was going to be vetoed on the basis of cost and the Minister of Finance made it very clear at the time, so I think what Mr Seymour has done is very sensible and has come up with a better outcome."