Stephen Harper has ratcheted up his warnings against a Liberal-led minority government, saying it would advance the cause of Quebec separatism.
Quoting comments made Sunday by Gilles Duceppe, the Conservative leader said the Bloc Québécois sees a Conservative majority government as a threat to an independent Quebec.
The Bloc Leader "has said that ... his objective is the sovereignty of Quebec and another Quebec referendum," Mr. Harper told reporters at a campaign event in this suburban Vancouver community, "and he has said that step one to achieving that is to stop a Conservative majority government in Ottawa."
At a Parti Quebecois policy convention that reaffirmed Pauline Marois' leadership Sunday, Mr. Duceppe said that Quebeckers had take a further step down the path to sovereignty.
"We have only one task to accomplish," he told delegates. "Elect the maximum number of sovereigntists in Ottawa and then we go to the next phase: electing a PQ government.
"A strong Bloc in Ottawa. The PQ in power in Quebec. And everything again becomes possible."
Mr. Harper is now making fear of an unstable Liberal-led minority government the dominant theme of campaign-rally speeches. And he has started to add national unity as a another reason for voters to shun such a government.
At a weekend rally in Burnaby, he warned against an unstable Parliament in which the Bloc Québécois, "a party that does not have the interests of this country at heart, will be looking to exploit any incoherence or instability for its own purposes. That must not be our future."
Since minority government arrived in Ottawa in 2004, both Liberal and Conservative governments have, at times, courted the support of the Bloc, which invariably votes for or against legislation based on whether it believes it advances Quebec's interests.
Liberal Leader Michael Ignatieff showed no interest in such talk.
"We have to de-dramatize all of this," he said when asked about the Conservative leader's comments. "I'm completely serene as to the possible choices of Quebec voters. We have worked with governments in the past that had sovereignist convictions. We maintained national unity in the country... I would address these challenges in the same way."
With polls showing the Conservatives still unable to break into majority-government territory, Mr. Harper's decision to play the national unity card could be seen as a late campaign attempt to further fuel his warnings against a Liberal-led coalition. The Liberals says they have no such plans.
But it is not the only card in his hand. At his final event during his weekend stay in the Vancouver area, Mr. Harper vowed to reintroduce legislation that would intern refugee claimants who arrived on Canada's shores en masse, as two groups of Tamils have by ship within the past 18 months.
Mr. Harper warned that permitting human smugglers to game the refugee system by filling ships with illegal immigrants undermined the integrity of the immigration and refugee process.
"The fairness of this system rests on equal treatment of applicants," he told a small gathering of Tory supporters, most of them belonging to a visible minority.
"And that principle of equal treatment is undermined when queue-jumping on a large scale is tolerated."
The opposition parties prevented an earlier version of the bill from making it through Parliament, on the grounds that the legislation unfairly targeted one group of refugee claimants who were themselves the victims of human smugglers.
The Conservatives have high hopes of winning over new Canadians in the May 2 election, through a policy that encourages legal immigration while cracking down on false claimants.