Two high-profile human rights groups have become the latest to withdraw from B.C.'s missing women inquiry, saying the process has become too flawed and unbalanced.

The inquiry into the failed Robert Pickton police investigation begins next Tuesday, but it will start amid the ongoing controversy over the government's decision not to fund a list of non-profit advocacy groups.

The provincial government refused a recommendation to cover the groups' legal bills, prompting several to withdraw from the proceedings, saying they simply can't afford to attend.

The B.C. Civil Liberties Association and Amnesty International have become the latest to bow out, although the groups say the issue for them isn't money, but fairness.

Michael Vonn of the civil liberties group says a process that excludes groups such as those working with women in Vancouver's Downtown Eastside while allowing the police to use government-funded lawyers is illegitimate and the association can't be involved.

Vonn says her group will offer guidance to two independent lawyers appointed by the inquiry, whose role will be to represent the broad interests of Downtown Eastside residents and aboriginals.