Prime Minister Harper argues that a Conservative majority is the only way to stop the sovereigntists in Quebec. The logic of his argument is that a divided parliament would be a weak parliament incapable of fighting off the sovereigntists. It is an odd argument to make because in the event (unlikely) of a referendum the two other federalists parties would ensure a strong response by the federal government.
In fact a better argument could be made that a conservative majority may indeed give the sovereignty movement just the ammunition it needs to get the Québécois fired up about leaving the federation. Only around twenty percent of the population in Quebec has an affinity for the Conservative party. That is not to say there is not a right wing in Quebec there surely is, but it is does not have the same priorities. A conservative majority would likely increase the distance the Québécois feel exists between themselves and the ROC.
Ironically a minority government would allow the Bloc to extract some concessions and those concessions would undermine the Bloc’s ability to claim that the federation could not be made to work. Harper’s inflexibility and brinkmanship style of politics would be just the type of federal government those wishing to have a referendum would like to have as a rival.