Woodworth said that Canadians don’t accept that “birth is a moment of magical transformation that changes a child from a non-human to a human being.”

“Motion 312 simply calls for a study of the evidence about when a child becomes a human being. It does not propose any answer to that question,” he said.

“Perhaps that ancient definition made sense when leeches and bloodletting were standard medical practices, but does it make medical sense in the 21st century?” he asked.

O’Connor said the legal definition has never been a medical test and he did not want to return to an era where women sought illegal and unsafe abortions.

NDP Justice Critic Francoise Boivin called the motion “a direct attack on a woman’s fundamental right to choose.” Supreme Court decisions, not a 400-year-old definition, have given “central place to a woman’s inalienable rights concerning her body,” she said.

The House will vote on the motion after it gets its next hour of debate, which Woodworth expects in June of September.