permitted to "cross the floor" switching party affiliation without having to first resign and restand for office under their new affiliation. Sitting members may also be dismissed from or voluntarily leave their party and become independents. As a result, the distribution of seats by party affiliation often fluctuates in between elections. Although several parties are typically represented in parliament, Canada has historically had two dominant political parties: the Liberal Party and the Conservative Party, which was preceded by the Progressive Conservative Party and the Conservative Party (1867–1942). Every government since Confederation has been either Liberal or Conservative with the exception of the Unionist government during World War I, which was a coalition of Conservatives and Liberals. However, in the 2011 federal election, the (NDP) New Democratic Party of Canada, came a close second, only behind by a few seats. While other parties have sometimes formed the Official Opposition, the 41st Parliament (2011-2015) was the first in which the Liberals did not form either the government or the Official Opposition. If a government loses a confidence motion, traditionally the prime minister will ask the governor general to call an election and the governor general follows that advice. However, the viceroy's compliance is not assured; the governor general also has the right to seek out another party leader who might be able to command the confidence of the House and ask him or her to form a government. This happened in 1926 and is referred to as the King-Byng Affair. The five-year time limitation is strictly applied to the life of the parliament or assembly in question—this body is not deemed to have been formed until the return of the writs and ceases to exist the moment it is dissolved. It is therefore possible to run slightly longer than five years between election days, as was the case between the 1930 and 1935 elections. Although the law has allowed for a five-year gap between elections, there have in fact only been two five-year gaps in the last 50 years: between 1974 and 1979 and between 1988 and 1993, and there have in fact been six general elections since 2000. It is also possible for a general election to be delayed should Canada be embroiled in a war or insurrection. This provision was enacted to allow Prime Minister Sir Robert Borden to delay a federal election for about a year during World War