A bill before Parliament today could see paid parental leave extended to six months.

This is the third attempt this year by Labour MP Sue Moroney to increase the allocation, and she believes everything has been pointing to it being a positive change.

LISTEN TO SUE MORONEY'S INTERVIEW WITH MIKE HOSKING ABOVE

"We have all the research and evidence which says that we're going to save a lot of money as a country if we go down this path. If we invest a little bit of money early then it's going to be great for everyone including those families," Moroney said.

Tick for Kids spokeswoman Lisa Woods said the few weeks they're fighting for is a crucial part of infant development that has life-long effects.

"Why aren't we doing it? We know that development in the early years is probably the most important time in one's life. I think we should be doing everything we can to ensure that parents have what they need in place to properly support their family and young children."

Woods said communities are rallying to bring New Zealand up to a global standard, using Britain - which has 39 weeks of parental leave - as an example.

"Research shows absolutely that policies such as parental leave with enough time are incredibly important and do make a difference to support early development."

Mothers and eight babies will be outside Parliament to represent the proposed eight week increase.