OTTAWA

Less than a week after MPs return to the Commons in mid-September, they're set to dive into a debate about Canada's 400-year-old definition of human being - a question that could develop into a full-blown discussion of abortion rights.

Conservative MP Stephen Woodworth confirms his motion to have a committee re-examine the Criminal Code provision that states a child becomes a human being only at the moment of complete birth is up for debate on September 21.

Woodworth says he's taken time over the summer to try to convince colleagues the Criminal Code "dehumanizes an entire class of people."

"I hope that I've influenced people, not only within our caucus, but in other parties too," he said.

Still, the motion faces an uphill battle, with Prime Minister Stephen Harper throwing the full weight of his office against it, telling Tory MPs that to vote for it would break his promise not to re-open the abortion debate.

Woodworth admits that could convince some Tory backbenchers to vote against the motion.

"I think that a lot of people do respect and admire the prime minister and will accept his advice on the subject," he said.

New Democrat and Bloc Quebecois MPs are expected to reject the motion, though some Liberals may break with their caucus colleagues to vote in favour.

Woodworth says he believes opposition to his motion is based on the fear that even considering whether children are human beings before complete birth could "cause some people to have second thoughts about our abortion practices."