WHAT'S AT STAKE: The election is for the 308 seats in Parliament's lower House of Commons. At least 155 seats are needed to form a majority government and gain a five-year mandate.

PREVIOUS PARLIAMENT: Prime Minister Stephen Harper's Conservative Party held 127 seats, compared with 95 for Stephane Dion's Liberal Party, 48 for the Bloc Quebecois and 30 for the New Democratic Party. Independents held four seats and four were vacant.

KEY ISSUES: Global credit crisis, slowing economy and carbon tax. Harper is the first G-7 leader to face election since the credit crisis worsened. He has been hurt by his slow reaction to the market meltdown. Dion is proposing an unpopular carbon tax to fight global warming. Harper says it will hurt the economy.

VOTING: Some 23.4 million Canadians are registered to vote. Polls open in Newfoundland at 7 a.m. EDT. Results expected within the hour after the last polls close at 10 p.m. EDT.

WHY: Harper has had a tenuous hold on power since the 2006 election and has struggled to gain the opposition support he needs to pass legislation. He says the Canadian leadership needs a clear mandate at a time of economic uncertainty.