OTTAWA—A power struggle between the elected House of Commons and the appointed Senate could erupt this week over the emotional issue of medical assistance in dying. Senators have already approved five amendments to Bill C−7, including two major changes that would expand access to assisted dying well beyond what MPs agreed to when they passed the bill in December. Senators are to begin final debate on the bill Tuesday before finally voting on their amended version and shipping it back to the Commons, which will have to decide whether to accept or reject some or all of the amendments. For now, Justice Minister David Lametti’s office won’t say if the Trudeau government is willing to accept any of the amendments. “We await the revised bill from the Senate and will respond to the final package … that they have put forward for inclusion at that time,” his office said in …