Frustrated family members, First Nations leaders and advocacy groups called Wednesday for a public inquiry into the missing and murdered women of British Columbia.

Stewart Phillip, Grand Chief of the Union of B.C. Indian Chiefs, said the inquiry must examine the actions of police surrounding the missing women of Vancouver's Downtown Eastside and those who vanished along Highway 16, between Prince George and Prince Rupert.

The native leaders and family members also called for Robert Pickton, previously convicted of murdering six women, to face a second trial on a remaining 20 murder charges.

Pickton, convicted in December 2007, used the Downtown Eastside neighbourhood as a hunting ground for his victims.

Phillip said they want the inquiry to go ahead right away -- even while Pickton exhausts his court process with appeals and the possible second trial.

The Crown has previously indicated that if Pickton's appeal fails, the remaining charges would not be heard at a second trial.

Calls for a public inquiry have been made on a number of occasions since police swarmed onto Pickton's property seven years ago.

The demand this time included a letter sent to Premier Gordon Campbell, Attorney General Wally Oppal and Solicitor General John van Dongen. The letter was signed by the United Native Nations, the Union of B.C. Indian Chiefs and the B.C. Civil Liberties Association.

"We are writing to you today to demand a full public inquiry into the ongoing issue of murdered and missing women from aboriginal communities."

At least 18 women have vanished along a 500-kilometre stretch of Highway 16, dubbed the Highway of Tears.

B.C.'s attorney general has previously said any decision about a possible inquiry would have to wait until Pickton's legal saga is finished.

The appeal of his convictions is set for the end of this month.

Phillip said family members are tired of waiting.

"I think the premier, the attorney general, the solicitor general need to understand that this issue has been ongoing for far too long," he said.

"It is a national disgrace and we've waited long enough for a full public inquiry."

He also suggested if an inquiry wasn't called the issue could rise again -- when the world is watching.

"This issue will be brought to the attention of the international community during the 2010 Olympic Games, it's as simple as that," said Phillip.

After the news conference, several people walked to a nearby mailbox to post the letters addressed to the premier, the attorney general and the solicitor general.

Maggie de Vries, sister of Sarah de Vries who is among those 20 other women Pickton is charged with killing, expressed deep frustration.

"It's wearing, it's exhausting, it's deeply and profoundly discouraging, and the longer we wait the less power we'll have to effect change because the less connected we'll be."

"We need to get to the bottom of what went on so we can stop it from continuing to happen," she said.

Vancouver City councillor Ellen Woodsworth said the story of missing and murdered women in B.C. is "the number one tragedy in Canada."

David Dennis, president of the UNN which represents off-reserve aboriginal people, said the disappearances along the northern highway can't be ignored.

"Our community sees what's happening along Highway 16 as exactly what happened in Vancouver's Downtown Eastside," said Dennis.