The ACT Party isn't exactly in favour of expanding government expenditure, but leader David Seymour does support increasing paid parental leave.

He's voted against Sue Moroney's bill to extend leave to 26 weeks for premature, disabled, or multiple births, instead choosing to support National on the issue.

Mr Seymour told Newstalk ZB's Mike Hosking Government Minister Michael Woodhouse has assured him the issues raised in Labour's bill will be addressed in National's version.

"Will I hold them to it - well, it's just like everything in Parliament I have one vote and you have to have 60.

"All I can do is speak up and say, 'I think this is the right thing to do', but ultimately they decide what to do."