TORONTO -- Marcia Brown Martel feels like she grew up alone.

After being taken by child welfare authorities from her aboriginal family and being adopted into a non-indigenous home, she lost her distinct language, traditions and ties to her community, resulting in a crushing sense of isolation.

The now-50-year-old says she wants to make sure no other child in Canada shares her experience, which is why she became the representative plaintiff in a class action lawsuit that claims a devastating loss of cultural identity was suffered by Ontario victims of the so-called "60s scoop."

Her hopes of having the lawsuit set a precedent, however, now lie with a judge who will hear arguments this week on whether the federal government should be allowed to appeal a court decision that gave the case the green light to proceed.

The lawsuit against the Canadian government refers to a period of time between the 1960s and the 1980s when thousands of aboriginal children were taken from their homes and placed with non-native families by child welfare services. None of its claims have been proven in court.

An Ontario court certified the case in July, but the federal government will ask Wednesday for leave to appeal that decision.

Martel finds the government's attempts at fighting the case frustrating.

"This is to change how Canada addresses its children," she said of the lawsuit. "When Canada chooses to appeal...they are appealing a fact of history."

According to its notice asking for leave to appeal, the government argued "there appears to be good reason to doubt the correctness" of the court order which certified the lawsuit as a class action.

Among its arguments, it said the judge erred "in improperly conflating the allegedly protected interest of cultural or aboriginal identity and the plaintiffs' claim for compensation for physical and psychological harm."

Martel was taken by child welfare services from her home on an Ontario First Nations reserve as a young child. She was adopted into a non-indigenous family at the age of nine, at which point her aboriginal name was changed.

"I lost my language, I lost my ability to communicate with my elders, I lost a lot," said the woman who only found out years later that a federal register listed her as deceased under the name she had been born with.

Martel cut ties with her adoptive family after she turned 18 and eventually returned to the reserve where she had been born. After years of slow and often painful re-integration, she is now the chief of the Beaverhouse First Nation in northern Ontario's Kirkland Lake region.

"I was an outsider. Those people didn't know me," she said. "I worked my way into the hearts of the community, one person at a time."

Throughout her childhood, Martel wasn't given much of an explanation about why she was no longer with her biological family.

"'Aboriginal people were always drinking and they couldn't look after their children anymore' -- that's what I was told," she said. "When I was about 12 I kind of wondered how is it possible that thousands of aboriginal people with families across the country could not look after their children anymore, how did that happen in one generation?"

The period covered by the suit stretches from December 1965 -- when the federal government signed an agreement with Ontario known as the Canada-Ontario Welfare Services Agreement -- until December 1984, when aboriginality was made an important factor in child protection and placement practices through the Child and Family Services Act.

In a written decision from Ontario's Superior Court of Justice which certified the lawsuit, a judge said the federal government was wrong to argue that the 60s scoop could not be questioned or challenged because all placement of children followed orders from courts that were supposed to act in the children's best interests.

"The plaintiffs are not challenging the actual court decisions that allowed the aboriginal children to be placed in non-aboriginal homes. There is no collateral attack in this proposed class action on the judicial decisions," wrote Justice Edward Belobaba.

"The plaintiffs are alleging that the Federal Crown had a duty or responsibility to protect and preserve the Indian children's culture and identity both when entering into the 1965 Agreement, and after the children were placed in the non-aboriginal homes, and failed to do so."

In certifying the suit, Belobaba narrowed the definition of those who could join the proceedings to children taken from Indian reserves in Ontario who were placed in non-aboriginal homes where they were not raised with aboriginal customs.

The lawsuit is being hailed by the plaintiffs' lawyer as a landmark case.

"A lost generation of children of the 60s scoop means children who lost their identities, lost connection with their culture, with their traditions, with their language," said Jeffery Wilson.

"It's important not only for First Nations children, it's important for children of all peoples all around the world that there should not be political solutions or expedient solutions that result in the loss of cultural identity for children....The issue is this should not ever happen again. These people have suffered remarkable pain."

The case has been working its way through the courts for over three years.

Plaintiffs asked for permission to put the case forward as a class action in February 2009, but the federal government successfully appealed certification of the proceedings, largely on a procedural point. A new hearing was then ordered in January this year. In July, the Ontario Superior Court of Justice certified the case after dismissing a Crown motion asking for the suit to be quashed.

If the government is granted leave to appeal after this week's hearing, Wilson said the case will enter another round of legal wrangling which will likely run well into 2015.

"We're spending a lot of taxpayer dollars and a lot of time on procedural points when Canada indicated at court that they regretted what happened and so the larger issue is why aren't the parties sitting down and attempting to resolve this issue," he said. "It is slow or frustrating for a lot of the potential claimants."