Maori Party co-leader Marama Fox said her party had a fundamental difference of opinion with National over a bill dealing with children in state care.
But she dismissed suggestions it could end the party's relationship with National, which it supports on confidence and supply.
"Our first option is to fight for our tamariki and you don't do that if you walk away," she told reporters at Parliament.
She believes the new organisation that will deal with children in state care should have a more Maori focus in the way it operates because so many children in state care are Maori.
"If we are to believe the statistics that say 63 per cent of children in the care of Child Youth and Family are Maori and 71 per cent of young people in prison are Maori, is the Government prepared to continue to negotiate with the Maori Party to ensure that the rebuild of Oranga Tamariki is done with a kaupapa Maori perspective?" she asked Prime Minister Bill English in Parliament.
She also objects to a provision in the Children Young Persons and Their Families (Oranga Tamariki) Legislation Bill which removes an existing requirement to place a priority on placing Maori children within their own whanau, hapu or iwi.
She says it could set up a new "stolen generation" and Dame Tariana Turia has talked about marching on Parliament in protest to it.
The bill was also the subject of discussion between ministers and the Iwi Chairs Forum at Waitangi earlier this month.
Questioned by the Greens in Parliament today, English said he would be concerned if anyone "as focused as Dame Tariana on the welfare of our children" felt that strongly.
He encouraged participation in the select committee process and to come up with proposals for changes.
"I think we do need to keep in mind, for those groups outside Parliament, that we do not want to let a philosophical discussion between adults get in the way of a better path for our children.
"Sometimes these things are easier to solve in practice than in theory."
Fox told reporters afterwards that it was important to get the bill right.
"We've already been assimilated and colonised once."
Asked if she would walk from Government over the issue, told reporters afterwards: "I'd walk over children before the Kermadecs any day of the week."
But she said she could not speak for the party on walking away.
The first option was to stay and fight.