I think the abortion 'debate' in Canada is largely obscured my American media debates on the issue. Even if the government were successful in defining life as beginning at conception, that would only be a small step in curtailing abortion rights.
An excerpt from the Supreme Court decision in
R v. Morgentaler:
State interference with bodily integrity and serious state-imposed psychological stress, at least in the criminal law context, constitutes a breach of security of the person. Section 251 clearly interferes with a woman's physical and bodily integrity. Forcing a woman, by threat of criminal sanction, to carry a foetus to term unless she meets certain criteria unrelated to her own priorities and aspirations, is a profound interference with a woman's body and thus an infringement of security of the person. A second breach of the right to security of the person occurs independently as a result of the delay in obtaining therapeutic abortions caused by the mandatory procedures of s. 251 which results in a higher probability of complications and greater risk. The harm to the psychological integrity of women seeking abortions was also clearly established.
(Section 251 refers to the Criminal Code of Canada, that section is what prohibited abortion except under certain circumstances. It was struck down in this decision)
The decision essentially stated that a woman has the right to choose not to be pregnant regardless of any other factors. Unlike the USA, we have on demand legal abortion available at any term in the pregnancy for that reason.
As an aside, I do think that life begins at conception but remain pro-choice regardless largely due to the above quoted facts. I view carrying a pregnancy to term in the same way as donating a kidney to someone. Its great if you do it, but if you can't/don't want to for whatever reason no one should be able to force you.