2005 United Kingdom general election

A general election was held in the United Kingdom on 5 May 2005, to elect 646 members to the House of Commons. The governing Labour Party led by Prime Minister Tony Blair won its third consecutive victory, with Blair becoming the second Labour leader after Harold Wilson to form three majority governments. However, its majority fell to 66 seats; the majority it won four years earlier had been of 167 seats. The UK media interpreted the results as an indicator of a breakdown in trust in the government, and especially in Blair.

This was the first time the Labour Party had won a third consecutive election, but would be the last election victory for Labour until 2024. The Liberal Democrats, led by Charles Kennedy, increased its seat count for a third consecutive election, netting the most seats in its history until 2024 and the most of any of the connected British Liberal parties since 1923. The Labour campaign emphasised a strong economy; however, Blair had suffered a decline in popularity, which was exacerbated by the controversial decision to send British troops to invade Iraq in 2003. Despite this, Labour mostly retained its leads over the Conservatives in opinion polls on economic competence and leadership, and Conservative leaders Iain Duncan Smith (2001–03) and Michael Howard (2003–05) struggled to capitalise on Blair's unpopularity, with the party consistently trailing behind Labour in the polls throughout the 2001–05 parliament. The Conservatives campaigned on policies such as immigration limits, improving poorly managed hospitals and reducing high crime rates. The Liberal Democrats took a strong stance against the Iraq War, particularly due to the absence of a second United Nations resolution; this anti-war position resonated with disenchanted Labour voters, leading to the Liberal Democrats achieving what was at that point their largest vote share in their history.