preferential voting has proven a significant handicap to coalition co-operation in Queensland and New South Wales, because significant numbers of voters do not express all useful preferences. Nomenclature Due to a disciplined coalition between the parties and their predecessors being in existence for almost 100 years with only a few brief cessations within a parliamentary system, most commentators and the general public often refer to the Coalition as if it were a single party. Polling and electoral results contain a two-party-preferred (TPP) vote which is based on Labor and the Coalition. The Australian Electoral Commission has distinguished between "traditional" (Coalition/Labor) two-party-preferred (TPP/2PP) contests, and "non-traditional" (Independent, Greens, Liberal vs National) two-candidate-preferred (TCP/2CP) contests. At the 2010 federal election, all eight seats which resulted in a two-candidate-preferred result were re-counted to also express a statistical-only "traditional" two-party-preferred result. Chronology Federal election results House of Representatives States and territories New South Wales A Coalition between the Liberal (and predecessors) and National parties has existed without interruption in New South Wales since 1927. Predecessors of the NSW Liberal Party, including the UAP, Nationalist Party and the Democratic Party, maintained a coalition with the Country Party (old name of National Party). The Liberal Party is led by Dominic Perrottet and the National Party by Paul Toole. The Coalition won the 2011 state election in a massive swing under Barry O'Farrell, the 2015 election with a reduced majority under Mike Baird, and the 2019 election under Gladys Berejiklian. New South Wales is the only state where the non-Labor Coalition has never broken, and yet has also never merged. This remained the case even in 2011, when the Liberals won a majority in their own right but still retained the Coalition. On 10 September 2020, the Nationals threatened to move to the crossbench over a dispute regarding koala protection laws, but the issue was resolved the next day and the Nationals remained in the Coalition. Queensland Due to Brisbane having a much smaller share of Queensland's population compared to the other state capitals, Queensland is the only state in which the Nationals have consistently been the stronger non-Labor party. The Nationals were the senior partner in the non-Labor Coalition from 1925 until the Coalition was broken in 1983. At an election held two months later, the Nationals under Joh Bjelke-Petersen came up one seat short of a majority, but later gained a majority when two Liberal