The Maori Party needs to explain why it is "kowtowing" to the Iwi Leaders Group which has become a de facto power force in national politics, activist Maori lawyer Annette Sykes says.

She is the keynote speaker for the Bruce Jesson Foundation's annual lecture tonight and is using her address to ask the party some hard questions.

An early supporter of the party, Ms Sykes says she's become critical of the influence the Iwi Leaders Group - chosen by the Iwi Leadership Forum and drawn from heads of runanga around the country - has had on policy development around issues such as the foreshore and seabed and emission's trading scheme.

Both laws provide outcomes that don't benefit Maori in any way, shape or form, but which the Iwi Leaders Group had a hand in shaping, Ms Sykes said.

"Why is it that the Maori Party changes its policy on every issue to meet the edicts of the Iwi Leaders Group, why are those MPs except one, Hone Harawira, constantly kowtowing to those policy preferences?"

The group, which included tribal runanga heads such as Tuku Morgan, Api Mahuika, Mark Solomon, Sonny Tau and Naida Glavish, was becoming a "one-stop shop" for policy development on a range of social, political and economic issues even though it had no mandate to do so.

"And frankly it doesn't cut it for me when I look around the room and I see people who are hugely unqualified to make decisions about the elimination of violence in Maori families or around priorities in tax regimes that ensure ... equity of outcome for Maori."

An "iwi elite caste" system was emerging with a right wing economic agenda that was showing no immediate trickle down benefits for Maori, who lived in struggling places such as Murupara or Kawerau.

The Herald asked Maori Party co-leaders whether the party was kowtowing to the group. In a written statement to the Herald Tariana Turia said the party had "opened the door" for the Iwi Leadership Forum to discuss issues directly with the Government.

"This is a significant step forward in iwi building a lasting relationship with the Government."

Ms Sykes isn't alone in her concern about the dynamic between the Iwi Leaders Group and the party. Some insiders have described disquiet about the way iwi leaders "culturally blackmail" members of Parliament when their policy aims are at odds with Maori Party policy.

Whaling and mining are two cases in point where the party has been against the practices in the past but have run up against iwi leaders who support commercial activity.

"Those MPs have been asked, well 'who are you? You're not iwi'. Those MPs have refrained from pointing out that they were elected by thousands of iwi with a clear mandate, which couldn't be said of all iwi leaders.