Labour's Sue Moroney is on the brink of winning her 3 year battle to increase paid parental leave.

Although United Future's Peter Dunne will wait until Wednesday to officially confirm his support, he looks likely to join the Maori Party, Greens and NZ First in sending her members bill to select committee.

Labour's Sue Moroney, the bill's sponsor, said she was "delighted". This is her second bid to the extend the entitlement, with a previous bill defeated in February.

"I think it means that the public support for extending paid parental leave to 26 leaves will be honoured. It also means that Parliament is reflecting the wishes of the public, which I think is really important."

But even if the legislation passes through all parliamentary stages, the fight may not be over. Finance Minister Bill English previously threatened to invoke a financial veto, saying the $500m price-tag was too costly. He's yet to say if he'll use the veto on this bill.

There will be cause for celebration if Moroney has squeezed more concessions from the Government. Her first bill prompted the Government to announce its own plans to increase the payments to 18 weeks from April 2016.

It's understood National is now preparing to announce further changes - giving extra leave to parents of twins or triplets, premature babies or those born with a disability - to the new Employment Standards bill which was introduced to Parliament earlier this month.

Hamilton-based Moroney said this alone would be "a victory."

That's what she proposed earlier this year, in a compromise to get her first bill over the line. She wrote an amendment which would grant 22 weeks leave to parents of babies born with disabilities, prematurely or in the case of multiple births, rising to 26 weeks in 2017.

The vote was deadlocked in February, which saw it fail. But five months later her Parental Leave and Employment Protection Amendment Bill - largely similar to her 2012 draft - was drawn from the ballot.

Workplace Safety Minister Michael Woodhouse agreed to look at extending the entitlement to parents of babies born with disabilities, prematurely or in the case of multiple births in order to convince ACT's David Seymour to vote against Moroney's bill.

It was expected that the provisions would be included in the new Employment Standards bill, which was introduced earlier this month.

Dunne says that doesn't go far enough and he has previously supported a universal 26 weeks.

But he is refusing to give any firm commitment to Moroney because he is sick of Labour using his vote to score political points.

"I've learnt from bitter experience with them that when I do - and it gives them the numbers - they go out and crow victory with no reference to the fact that it is my vote. And when I don't they go out and put the boot in. So they now find out when my vote is cast."

Seymour said Tuesday he would continue to oppose 26 weeks leave for all.

A spokesman for Woodhouse said he could not confirm an 'announcement' in the next day or two.



"But I can confirm that we're continuing to have discussions with Mr Seymour in good faith around the issues that he's raised regarding Paid Parental Leave."