First Nations chiefs have backed a resolution calling on Marion Buller, the chief commissioner of the missing and murdered Indigenous women and girls inquiry, to resign.

By a vote of 48 to 15, chiefs gathered at the Assembly of First Nations special meeting in Ottawa said they want the federal government to both extend the time of the inquiry — by tacking on an extra two years beyond the scheduled completion date of November 2018 — but also "reset" the process by appointing a new leader.

The Liberal government does not have to adhere to the non-binding resolution, and, in an interview with CBC News before the vote, Buller said she had no plans to step aside.

"I came into this knowing there would be a great deal of criticism, and I always welcome informed, constructive criticism because it's helped us do our job better," she said. "The commissioners and I intend to continue. The families and survivors all across have told us how important this work is and how we need to continue to shine a light on the truth, to make our final report and recommendations, because they deserve nothing less."

When asked if she thought people supportive of the inquiry are having their voices drowned out by those in opposition, she said that's a question for the media to ask itself as it routinely gives a platform to those critical of the inquiry. "What I hear in hearings ... families are very supportive of the work we're doing. It's up to you in the media to decide, I'm not going to tell you who to talk to."

Chief Peter Collins, of Fort William First Nation, first introduced the motion at the assembly calling for an extension without the condition Buller leave her post, but agreed to the addition — moved by Judy Wilson, chief of the Neskonlith Indian Band in B.C. — after it became clear most chiefs were unhappy with the commissioner's leadership.

Buller, who had only minutes earlier made a presentation to the AFN, received little if any applause from chiefs when she defended the inquiry's work, and recounted stories of families who are supportive of the study. Rather, when it came time for a question and answer session, she faced an onslaught of criticism.

The most scathing came from Grand Chief Sheila North Wilson, who heads the Manitoba Keewatinowi Okimakanak, a group of some 30 First Nations in the province's north.

'You're not a brilliant commissioner'

"You're not a brilliant commissioner for this inquiry. Sorry, and not sorry at the same time. We need to see you resign. All of you commissioners should resign but for me personally it's you ... the commission is falling apart."

In an interview after her public rebuke of Buller, Wilson said Buller is too cold and "heartless" in her approach to families and survivors. "This inquiry needs to go on, but not under her leadership. I'm sure she's a brilliant person, but she's not a brilliant commissioner."

Many critics believe the inquiry is too focused on gathering testimony from families and survivors, and has not honed in on studying concrete solutions to solve the preponderance of violence directed at Indigenous women.

There is also a concern that the inquiry has not done enough to study the conduct of police and institutional racism. Buller has vowed to study police conduct, and "investigate the investigators," but has called on the federal government and provinces to work together to establish a new, separate body to which families can be referred if they feel they got short shrift from police in the first place.

Sheila North Wilson, Grand Chief of Manitoba Keewatinowi Okimakinak, was scathing in her criticism of MMIWG chief commissioner Marion Buller. (Jeff Stapleton/CBC)

Chief Janice Henderson, of Mitaanjigamiing First Nation in northern Ontario, the original seconder of the motion, pulled her support because she said removing Buller would simply delay the proceedings that are already beset with staffing issues.

She said she just testified at the inquiry's family meeting in Thunder Bay, Ont., this week and was impressed with the level of care afforded to her and others who came forward to tell their stories. Henderson's mother, and two of her aunts, were murdered.

"The commissioners were very compassionate. They created a safe environment for families. I support the inquiry, I support the process. This needs to go to an extension because three short days [in Thunder Bay] isn't sufficient for families to get there and be able to give their statements," she said.

Donald Maracle, the chief of the Mohawks of the Bay of Quinte in southern Ontario, told other chiefs he backed Buller and forcing her out now would be a step backwards. "I think if you get rid of the commissioner, it will paralyze the operation and slow things down," he said.

Indigenous Services Minister Jane Philpott said the inquiry is the responsibility of her counterpart, Crown-Indigenous Relations Minister Carolyn Bennett, and she did not want to pre-empt her reaction to the motion — but added, "[Bennett] is determined that the inquiry will be successful, the families will remain at the centre, and she'll work with the commissioners and all other parties to get there."

In a statement Thursday, Bennett's office said the minister would consider a formal request for an extension when they receive one from the commissioners, but ignored questions about the AFN's resolution to remove Buller.