Maverick Maori Party MP Hone Harawira won't be voting for the new foreshore and seabed legislation that his party fought for.

Prime Minister John Key said party co-leader Tariana Turia told him of Mr Harawira's decision this morning.

"It's highly predictable and quite frankly we would never be able to pass legislation that would satisfy Hone Harawira nor should we because that would not reflect the views of the majority of New Zealanders," Mr Key told reporters.

"If he doesn't vote for it, I don't care."

The loss of one vote will not stop the bill passing its first reading this week but shows a split in Maori Party ranks.

The Maori Party was formed when Mrs Turia quit Labour over its foreshore and seabed policy.

Her party has fought to get agreement on repealing that law and replacing it with one that gives Maori more rights but Mr Harawira does not think it goes far enough.