the senate has threatened to push back. my view is that, if they do, the government will need to modify it's senate reform policies.
the last time this happened was abortion, and the senate did the right thing then in blocking an obviously unconstitutional law, but the situation is not comparable - this law is not clearly unconstitutional. i think it is, but not clearly so. the court needs to make that choice, not the senate; the senate is just interfering, overstepping, meddling.
https://www.thestar.com/news/canada/2016/06/16/liberals-reject-senate-proposal-to-cut-near-death-proviso-in-assisted-dying-bill.html
if the senate has serious concerns about the constitutionality of the legislation, it should request a review from the supreme court rather than take it upon itself to become self-appointed constitutional scholars.