It seems I am not the only one to think Stephen Harper may be warming up too quickly to a referendum on the Senate: Vote on Senate 'premature,' PM warned. Here is Preston Manning's view:
Mr. Manning said Tuesday that he supports the idea of a referendum, but that the question cannot be solely about abolition. Rather, Canadians should be asked to choose between abolition and reform. He also said that a referendum can be fair only if the government were to finance both sides of the issue so Canadians could be well-informed about the options before they go to the polls.
And now Liberal leader Stéphane Dion:
Mr. Dion said a referendum would be expensive and almost useless because of the possibility it would divide the country. He noted that even if a majority voted in favour, some provinces would almost certainly be opposed and that a constitutional change of such significance would require unanimity among the provinces. He suggested that the Prime Minister convene a meeting of premiers before pressing ahead with a referendum.
I suspect that most constitutional scholars would hold that a referendum on such an issue could be at most only advisory, and that the issue would have to be decided according to the procedures laid out in section 41 of the Constitution Act, 1982, requiring unanimous consent of each provincial legislature. Although the possibility of abolishing the Senate is not mentioned in this act, its existence is assumed in 41(1)(b). Of course, one might conceivably make a case, under section 42(b), that the general amending formula in 38(1) would be sufficient, viz., approval by both chambers of Parliament and at least 7 provinces containing at least 50 percent of Canada's population. Yet that subsection refers only to "the powers of the Senate and the method of selecting Senators," which would seem to exclude abolition.
Thus I believe Dion is on solid constitutional ground, and both Manning and Dion are on solid political ground. Harper would be wise to heed their warnings.