Will British Columbia decide the election's outcome?

It is often said that federal elections are decided before many British Columbians even vote. But with the polls suggesting a close three-way race countrywide, Canadians may have to wait until the ballots are counted on the West Coast late on election night before knowing which party will form the next government.

In 10 of the last 12 elections going back to 1974, the winning party had enough seats to form a government without needing a single MP from British Columbia.

In 2006, the Conservatives and Liberals were still technically close enough in the seat count outside of British Columbia for the outcome to still be in question, but the margin between the two parties was large enough that anything but a Conservative victory was unlikely.

• Poll Tracker | Follow the latest numbers
• Analysis | How a recession would shake up the election campaign
• Find out where you fit with Vote Compass 
• Recession is latest sign of Harper's 'lost decade,' political rivals say

The 1979 election was the last one in which British Columbians cast decisive ballots: Joe Clark's Tories had won 117 seats outside of B.C. to 113 for the Liberals. Clark's big win in the province secured his (short-lived) minority government.

Polling stations in British Columbia and Yukon will be open later than anywhere else on Oct. 19. But factoring in the time required to count votes from earlier regions, the 30 minutes their voting booths remain open is unlikely to be long enough to have a good idea of who is going to win the election before casting a ballot.

But Canadians may have to wait until B.C. ballots are counted before learning who will win.

Based on current seat projections, if an election were held today, the Liberals would come out of Atlantic Canada, where the polls close earliest, with some 21 seats, versus eight for the NDP and three for the Conservatives.

The next provinces to end their voting hours (Alberta, Saskatchewan, Manitoba, Ontario and Quebec) would boost the New Democrats to the top of the table with 108 seats, with 102 going to the Conservatives and 85 to the Liberals.

That would leave British Columbia with the final word. As it currently stands, B.C. would tip the balance toward the NDP, as it is projected to win 16 to 22 seats in the province. The Conservatives are slated to win between nine and 18 seats, the Liberals between seven and 10, and the Greens one. The Conservatives would thus need a big boost, or better performances outside of British Columbia, in order to come out ahead.

But that is based on current levels of support, which undoubtedly will ebb and flow between now and election day. Taking a wider look at the numbers, however, what is the likelihood that Canadians will be kept in suspense until the votes are counted in B.C.?

B.C. key to majority

With the polls where they are today, the path to a minority government will run in part through B.C. But a majority NDP victory would very likely depend on the votes of British Columbians.

With current estimates of where the NDP is in play, the party would likely find itself about 20 seats short of the majority marker of 170 outside of B.C. if it were on path to a big win Canada-wide.

If the country were swinging toward the New Democrats in such a dramatic fashion, winning 20 of the 42 seats in British Columbia would not be a high bar to meet. Nevertheless, British Columbians could make the difference depending on whether they follow the country or vote against the NDP bandwagon.

A Conservative majority?

If, instead, Canada moves back toward the Conservatives, Canadians may not find out whether it is a majority or minority victory until the ballots are counted in British Columbia.

The path to a minority victory can be forged outside of the province, particularly if the Conservatives do well in Ontario. Without a strong showing in B.C., the Conservatives could still eke out a slim minority win. But that may not be enough to survive in government for long.

For the Conservatives to win a majority, they will need the backing of a large number of British Columbians — but not necessarily a majority of them. Based on where the Conservatives could currently win seats in a best-case scenario, the party could find itself about 15 short of a majority outside of British Columbia. Winning 15 of the 42 seats in the province should not be too tall an order for the Tories, as that would still represent a drop of six seats from their 2011 performance.

B.C. needed for a Liberal minority

The path to a majority government for the Liberals is currently not in the cards based on their current standings in the polls, but a minority government is achievable. And here again, it could depend on the votes of British Columbians.

A best-case scenario finds the Liberals with 113 seats outside of B.C., which would likely not be enough for them to take the plurality of seats on offer in the House of Commons. The party would not need many seats in B.C. to get to the minimum likely threshold for a minority government, but it would still require some big gains. The Liberals won just two seats in the province in 2011. But if British Columbians swing to the party, they have a good chance of backing the next government.

In the end, that is likely the case for all three of the major federal parties. With Ontario split three ways, it is not on track to deliver the huge number of seats that parties have won in the past on their way to forming government. With Quebec, the Prairie provinces, and Atlantic Canada each backing one party in large numbers, that leaves British Columbia with the potential to hold the balance of power.

That's a responsibility the province has not had in 36 years.

CBC's Poll Tracker aggregates all publicly released polls, weighing them by sample size, date and the polling firm's accuracy record. Upper and lower ranges are based on how polls have performed in other recent elections. The seat projection model makes individual projections for all ridings in the country, based on regional shifts in support since the 2011 election and taking into account other factors such as incumbency. The projections are subject to the margins of error of the opinion polls included in the model, as well as the unpredictable nature of politics at the riding level. The polls included in the model vary in size, date and method, and have not been individually verified by the CBC. You can read the full methodology here.