Canada's political leaders have made their final appeals to voters ahead of Monday's general election.
Opinion polls favour Mr Harper (L) over Mr Martin
Some opinion polls put Steven Harper's opposition Conservatives 10 points ahead of the governing Liberals.
PM Paul Martin again said his opponent was a dangerous neo-conservative, while Mr Harper pointed to a number of scandals the government had suffered.
Conservatives are hoping the nation's 22.7 million voters will end 12 years of Liberal rule.
Mr Martin was elected with a minority government only 18 months ago but lost a no-confidence vote late last year.
Political leaders headed across the country over the weekend to try to persuade any undecided voters.
Voters in 60,000 polling stations across six time zones will choose from candidates including the Greens, the left-wing New Democratic Party and French-speaking separatist Bloc Quebecois - but the main battle will be between the Liberals and Conservatives.
The Bloc Quebecois' Gilles Duceppe makes a final plea to voters
Mr Harper, 46, said in Winnipeg on Sunday: "We can win because it is time for a change, time to move forward, time to get beyond the scandals and investigations and corruption.
"Let the Liberals claim, for Canada, this is as good as it gets. I know for our Canada, the best is yet to come."
Mr Martin, 67, told supporters in Vancouver: "We have the numbers. We can stop Stephen Harper. We can elect a government that reflects the Canada we believe in.
"It is up to us. So I am asking you to dig deeper, go further, to fight harder."
However, opinion polls suggest a Conservative win, with some indicating the Liberals may get their lowest percentage of votes in any election since 1867.
The Liberals have been focusing on economic successes, pointing to eight consecutive budget surpluses.
But the BBC's Lee Carter in Toronto says accusations that Mr Martin's party is scandal-ridden and prone to corruption are beginning to stick..
Our correspondent says the Conservatives are even making inroads in the French-speaking province of Quebec, where they have been frozen out of for more than a decade.
Mr Harper has promised tax cuts, a crime crackdown and cleaner government.
The Liberals say he is too extreme in his views on issues such as abortion and gay marriage and will threaten social programmes.