A poll on Sunday showed Harper's Conservatives maintained a comfortable lead over the second-place Liberals, but lacked sufficient support to take enough parliamentary seats to rise above their current status of needing opposition support to pass legislation.
Liberal leader Stephane Dion lashed out at New Democratic Party leader Jack Layton, warning that splitting support between the country's left-leaning parties would allow Harper to take power as he had in the last election.
"In 2006 Jack Layton told Canadians 'lend me your vote'... well to Jack Layton we should say we want our votes back with interest," Dion told a rally in Ontario, where he also accused Harper of running a campaign of lies.
Layton, whose NDP has polled in third place, was also in Ontario urging voters in communities hit by the downturn in the auto industry to follow their consciences and support him.
Harper was in Quebec, where Conservative hopes of picking up seats have faded with the separatist Bloc Quebecois capitalizing on anger over his calls to cut arts funding and toughen laws for underage criminals.
Harper called the election in September, saying the current minority government had become unworkable.
The party leaders who have struggled at times even to keep the campaign in the headlines, faced an added obstacle Sunday of mustering voter attention when Canadians are celebrating the national Thanksgiving holiday weekend.
A tracking poll by Harris/Decima- Canadian Press showed the Conservatives steady at 35 percent, with the Liberals up 1 point at 26 percent, followed by the NDP at 18 percent, Bloc Quebecois up 1 point to 10 percent and the Green Party slipping 2 points to 9 percent.
Pollster Bruce Anderson said that with the Bloc's recent surge in Quebec, the Conservatives' hopes of a majority likely depend on Ontario where they have shown some momentum but where the Liberals remain highly competitive.
"Given the volatility we have seen, it would be safer to assume that there could be more movement yet," Anderson said in a note.
Pollsters say that traditionally a party must win 38 to 40 percent of the vote nationally to seize a majority of 308 seats in the House of Commons, where the Conservatives now hold 127 seats.
The Harris/Decima survey interviews 300 people nightly over a three-day period and carries a margin of error of 2.8 percent.
