Prime Minister John Key says giving the Te Urewera National Park to Tuhoe could have opened the way for other iwi to put strong cases for ownership of national parks, including Whanganui, Egmont, Ngauruhoe and possibly Aoraki/Mt Cook.

Mr Key said yesterday his decision to veto Tuhoe's hopes of getting ownership of the Te Urewera National Park came after he received advice on how such a move would impact on other settlements.

"There are about three or four other iwi, not exactly in the same position as Tuhoe but in similar positions that I believe would have expected the same outcome in their Treaty settlements had we agreed to fully vest the park."

He listed the Egmont National Park around Mt Taranaki and the Whanganui National Park as cases where iwi could make such an argument. There was also an issue over Mt Ngauruhoe for Tuwharetoa. It was also possible Ngai Tahu could raise an issue over Aoraki/Mt Cook, despite its settlement being deemed full and final.

The Ngai Tahu settlement includes provision for Aoraki/Mt Cook to be gifted to the iwi and then re-gifted to the nation. However, that clause has not yet been acted upon and it is up to Ngai Tahu to decide when to trigger it.

Mr Key's justification for the decision was rejected by Maori Party co-leader Tariana Turia.

"None of those cases is similar to Tuhoe so you can't compare those iwi to Tuhoe. This is an opportunity for the Crown to make good and doing what is right, not looking over the shoulder at other iwi and trying to make Tuhoe think that because of those other iwi they're not going to get their settlement."

Facing his seventh day of questioning on his Tuhoe decision, Mr Key maintained it was the correct move and continued to deny that Tuhoe were ever led to believe it was a done deal. He said ownership of the park was included as an option by negotiators after Tuhoe had rejected all other alternatives put to them.

"That one was an option, but not one that found favour with me. As Prime Minister I am responsible to the people of New Zealand to support [Treaty] settlements which I believe represent the best interests of all New Zealanders. In my view, this is a step too far."

He had rejected it himself after discussions with several of his ministers.

Mr Key said he was confident his relationship with the Maori Party was "in good shape" despite the decision and his later claim its co-leader Tariana Turia was "fine" with it. The claim had angered Mrs Turia who had issued a statement criticising Mr Key's decision as showing a lack of integrity.

Yesterday he said he had spoken to Mrs Turia but would not say if he had apologised to her.

"I'm learning rapidly not to relay every conversation I have with her through [the media] but I'm satisfied the relationship is in good shape."

He said it was obvious the Maori Party was disappointed and that Mrs Turia personally felt very deeply about it.

"[She] believes they've been a iwi which has been terribly affected and she's quite right in terms of the historical position, but that doesn't mean we are going to vest a national park solely in their rights."

He said he remained hopeful of achieving the goal of settling all historic claims by 2014 "but I'm not prepared to do that at any cost".

After facing criticism from the Maori Party about going public with the decision, despite negotiations still being under way, Mr Key said the iwi had asked him to make the decision public so it was known before a hui Tuhoe had organised for last Friday. That hui was cancelled.