An Ontario woman is asking the courts to officially recognize her as the third legal parent of a five-year-old boy she is raising with her same-sex partner.
The application, if allowed, is believed to mark the first time in Canada that a child would have more than two legal parents.
The biological father and mother and her female partner must remain anonymous because of a court ruling protecting their identities.
"The family has evolved over the years in a way that the law should recognize the reality of this little boy," the father's lawyer, Alfred Mamo, told The Canadian Press
The original application made three years ago, which seeks a declaration of parenthood, would give the mother's same-sex partner the same rights as if she were a biological parent.
That application failed because the family court ruled it did not have the authority to make a judgment on the case.
The applicant appealed, arguing she was in a special situation because same-sex couples require assisted human reproduction.
She contended that if the law does not make room for three legal parents, it is a violation of the Charter of Rights and Freedoms guarantee of equality.
"It's discriminatory, because one of them gets legally recognized ... the non-biological mother is equally part of the process except for the biological bits,'' said the woman's lawyer, Peter Jervis.
The case has provoked heated response from several religious groups, including the Evangelical Fellowship of Canada, the Catholic Civil Rights League, the Christian Legal Fellowship and Focus on the Family.
The Alliance for Marriage and Family has filed a brief on behalf of these groups, stating its belief children can only have two parents under family law in Canada.
Janet Epp Buckingham of the Evangelical Fellowship of Canada said that to change the law "You would need to have the full hearings in the provincial parliament and it should be a legislated change.''
Meanwhile, the Institute of Marriage and Family Canada has issued a statement arguing that reproductive technologies are redefining parenthood in ways that may hurt children.
They cited a report that says the growing use of egg and sperm donors, high rates of divorce and single-parent childbearing and support for same-sex marriage are putting the interests of adults before the needs of children.
"Radical changes to our public norm of parenthood in law and public policy are challenging one of the most fundamental tasks of human culture, namely the struggle to forge strong healthy connections between children and their biological parents," says Dan Cere, director of the Institute for the Study of Marriage, Law and Culture, one of the four think tanks sponsoring the report, and McGill University professor of religion, ethics, and public policy.
"Breaking ranks with the United Nations Convention on the Rights of the Child, Canadian law now elevates the rights of adults to children over the rights of children to their birth parents."
With files from The Canadian Press