Canada's federal election on Monday is too close to call, raising the prospect of a potentially destabilizing political battle between the ruling Conservatives and opposition parties, according to Reuters. Polls show the Conservatives are set to win the most seats in the 308-seat House of Commons but it is impossible to say whether they will capture a majority, or if they can find opposition support to make a minority government work. Canada -- the largest single supplier of energy to the United States -- has not seen such an unpredictable election for more than three decades, McGill University political science professor Richard Schultz told Reuters. "It's so up in the air ... as a close watcher (of politics), I'm as confused as anyone by this," he said. The right-of-center Conservatives have been in power since early 2006 with two successive minority governments, which required them to gain opposition support to pass key bills. They insist they need a majority to keep taxes low and ensure Canada continues to recover from the global crisis. Prime Minister Stephen Harper -- who has run a relentlessly negative campaign -- says if he falls short of his goal, center-left opposition parties will oust him and create a "dangerous" coalition guaranteed to destroy the economy. His main target is the left-leaning New Democrats, running a strong second in the polls. They promise to raise corporate taxes, increase social spending and bring in a cap and trade system to cut emissions of greenhouse gases. "The risk, a very real risk if we do not get a majority, is a New Democrat-led government promising the moon and soon seeing the consequences -- raising taxes, killing jobs, setting families back ... and sooner rather than later, yet another election," Harper told a rally in Atlantic Canada on Sunday. VOTE-SPLITTING Harper could benefit from vote-splitting between the New Democrats and their Liberal rivals and eke out a majority, which would earn him a fixed four-year term in power. But an Ekos poll for the iPolitics website released on Sunday made that eventuality look less likely. Ekos put public support for the Conservatives at 34.6 percent, with the New Democrats close behind on 31.4 percent and the Liberals on 20.4 percent. This strongly suggests the election will produce another Conservative minority. A Conservative-led coalition might be more stable but is not an option, given Harper's attacks on opposition parties and his highly uncompromising style of governing. Canada's economy is one of the best performing among rich industrialized nations, although the deficit spiraled to record levels as the Conservatives spent heavily to pull Canada out of recession. All three parties promise to balance the budget within a few years, a factor that reassures markets. "We shall see if investors remain so sanguine on Tuesday morning, but they certainly aren't jumping to any conclusions yet," said Douglas Porter of BMO Capital Markets. The main reason for the political uncertainty is the unexpected rise of the New Democrats, a pro-labor party that has never held power and started the campaign in third place. Leader Jack Layton was upbeat from the start, urging voters to abandon the larger two parties and give him a chance. If the New Democrats and Liberals together win more seats than the Conservatives, Harper would have to decide whether to compromise or force a showdown. His first test would come within weeks in a speech to Parliament outlining his plans. This is a confidence measure and if opposition parties toppled the Conservatives, they would almost certainly be given a chance to create a government without another election.