OTTAWA - Families of missing and murdered women are raising their voices in defence of the national public inquiry as it faces a stream of criticism from advocates and indigenous leaders.

Bernie Williams, who has spent more than 30 years on Vancouver's Downtown Eastside raising awareness about missing and murdered indigenous women, is urging families to keep faith in the process.

She says the commissioners must proceed with their work very carefully because there can be no room for mistakes, adding they're well aware of horrific problems plaguing communities, including rampant sexual abuse.

Five commissioners have been given two years and $53.8 million to conduct the study.

Chief commissioner Marion Buller says more time and resources are needed, but the commission has yet to submit an application to the Liberal government for an extension.

The first public hearings will begin next week in Whitehorse.