Senators are expected to vote Wednesday on whether to support the Liberal government's doctor-assisted dying bill.
The Red Chamber has spent a week proposing changes to Bill C-14, most notably removing the requirement that a patient be at the end of life to qualify for medical assistance in dying.
If the bill passes in the Senate, it will make its way to the Commons for further review, where the changes can be accepted or rejected – but it must go back to the Senate to pass into law.
While the Liberals have said they will consider all amendments made in the Senate, the government has strongly suggested it wants to reject the change that a patient's natural death need not be "reasonably foreseeable."
"This amendment is a substantial change to the balance that we worked very hard to achieve in C-14," Justice Minister Jody Wilson-Raybould told reporters on Tuesday.
Other amendments passed by the Senate include requiring a palliative care consultation, banning beneficiaries from helping a patient self-administer medication, increased reporting requirements for the health minister and independent studies on other issues such as advance requests to be completed within two years.
Independent Senator Frances Lankin, who supported the removal of end-of-life criteria, said she believes the bill in its original form is unconstitutional, but admitted there are competing views.
"I'm leaning towards accepting what comes back from the duly-elected Parliament, but I remain concerned," she said.