A leadership election is a political contest held in various countries by which the members of a political party determine who will be the leader of their party. Generally, any political party can determine its own rules governing how and when a leadership election is to be held for that party. In the United Kingdom, for example: A leadership election may be required at intervals set by party rules, or it may be held in response to a certain proportion of those eligible to vote expressing a lack of confidence in the current leadership. In the UK Conservative Party, for example, "a leadership election can be triggered by a vote of no confidence by Conservative MPs in their current leader". Strictly speaking, a leadership election is a completely internal affair. An intra-party election held to select its candidates for external offices, such as a president, governor, prime minister or member of a legislature is called a primary election. Leadership elections have great importance in parliamentary systems, where the chief executive (e.g.: a Prime Minister) derives their mandate from a parliamentary majority and the party's internal leaders hold frontbench positions within the parliament, if not outright serving in a ministerial post – whether as Prime Minister in the case of the leading government party, or another Ministerial post for junior coalition partners. For that reason, most parliamentary systems do not hold dedicated Prime Ministerial primaries at all, but simply select their internal leader as their candidate for Prime Minister. However, leadership elections are often similar to primary elections in that in the vast majority of instances, a party's leader will become prime minister (in a federal election) or premier/chief minister/first minister (in a province, state, territory, or other first-level administrative subdivision) should their party enter government with the most seats. Thus, a leadership election is also often considered to be one for the party's de facto candidate for prime minister or premier/chief minister/first minister, just as a primary is one for a party's candidate for president. An electoral alliance, which is composed of multiple parties each with its own separate leader and organs, may also hold a common Prime Ministerial primary as in the 2021 Hungarian opposition primary, or a single party may wish to retain its leader but select someone else as its Prime Ministerial candidate, as the Portuguese Socialist Party has done in 2014. In presidential and semi-presidential systems,