"By giving the green light to research on embryos who remain after fertility treatments, Bill C-13 fails to protect the human embryo," the bishops' conference said in a statement released Wednesday.
"Over the course of many months of testimony, [the House of Commons] Standing Committee on Health heard both scientists and ethicists define the embryo as a human being," the statement said.
"Even those who consider the term 'human being' more philosophical than biological would agree that embryos are human, that we all began as embryos, that human life unfolds as a continuum, that in a very real sense the embryo is one of us," it continued. "Both reason and faith inform the Catholic position that 'the human being is to be respected and treated as a person' from the beginning."
Nonetheless, the bishops' statement noted: "There is much that is positive in Bill C-13 and that can be supported such as the prohibitions concerning animal/human hybrids, germ-line alteration, the ban on commercial surrogacy, the prohibition on the marketing of embryos and gametes and the intention to prohibit cloning for the purposes of reproduction or research."
The bishops' conference also noted the argument that embryo research could draw something good out of tiny human being who are doomed to die anyway.
"It is not necessary that we do something with these embryos so that some good or meaning will be given to their lives," the statement said.
"There is good and meaning in their lives simply because they are intrinsically human which also means from a faith perspective that they are known and loved by God," it said.
The statement added: "While we realize that our position on protection of the embryo will preclude embryonic stem cell research in which so many hopes have been invested, we are convinced that adult stem cell research, which is showing remarkable promise, can still go forward and has every potential to fulfill those hopes."