Ulster Unionist Party

The Ulster Unionist Party (UUP) – sometimes referred to as the Official Unionist Party (OUP) or, in a historic sense, simply the Unionist Party – is the older of the two main unionist political parties in Northern Ireland. Before the split in unionism in the late 1960s, when the former Protestant Unionist Party began to attract more hardline support away from the UUP, it governed Northern Ireland between 1921 and 1972 as the sole major unionist party. It continued to be supported by most unionist voters throughout the period known as the Troubles.

The UUP has lost support among Northern Ireland's unionist and Protestant community to the Democratic Unionist Party (DUP) in successive elections at all levels of government since 1999. The party is currently led by Mike Nesbitt.

In 2009 the party agreed to an electoral alliance with the Conservative Party and the two parties fielded joint candidates for elections to the House of Commons and the European Parliament under the banner of "Ulster Conservatives and Unionists – New Force" (UCUNF). Literature and the website for the 2009 European Parliament election used "Conservatives and Unionists" as the short name. The party held its European seat but lost all its Westminster seats when their sole MP left the party in protest at the alliance and ran as an Independent.