[stan_rogers]

To put it simply, yes, you're wrong. (Please note that that's the simple answer, not the fully-played-out-in-the-courts answer.) Although we aren't quite in the same position as the USA and their federal/state splits, there are things that are specifically under provincial control and jurisdiction. As one might suppose, this is largely because of Quebec and its legal history before pre-Confederation Canadian unification, but that's not the full answer either. A lot of federal policy is applied through transfer payments since while the federal government can base those payments on provincial compliance, it has no direct control over things that are under strict provincial jurisdiction. In this case, the Supreme Court will have the final word if there is provincial objection; the law as it stands is equivalent to a constitutional change without going through the constitutional change process.

[jgmjgm]

I appreciate your answer on this. No offense, but I don't believe you. Would you mind supplying more information beyond simply a statement? Do you have expertise in this area? (Are you a lawyer?) I know this is a big ask because we are all busy people, but you did answer this in a rather authoritative response...

I'm not trying to be adversarial, it's just that this answer doesn't provide anything but a "proof by anonymous internet authority" vague kind of answer.

[throwaway2048]

Provinces were allowed to override federal criminal law with respect to safe injection sites (federal police in canada were standing outside and arresting addicts as they came in/out)

Note, most local police in canada are federal.

The supreme court ruled that the provincial health concerns overrode federal criminal ones.

https://en.wikipedia.org/wiki/Canada_(AG)_v_PHS_Community_Se...

This sort of thing has a long history in Canada. Although in theory the federal government is much stronger than the USA federal government with respect to Provinces/States, the reality has played out significantly differently. Likely because of the influence of Quebec on canadian regional politics, and the fact there are fewer provinces than there are American states.

[jgmjgm]

Thanks for the response and example.

Yes, actually re-reading OP and your comments made me realize that I actually agree with the parent post. Don't know what I was thinking at the time I originally read it.

[Waterluvian]

And this would be why they studied if this law would be constitutional? Ie. To avoid the embarassment of a province challenging it.

So it's not that a province can just turn off or ignore federal law, it's that it might have a case to challenge it in court?

I think I understand a little better now. Thank you for responding.