The examples and perspective in this article deal primarily with Europe and do not represent a worldwide view of the subject. (September 2018) (Learn how and when to remove this template message)
A grand coalition is an arrangement in a multi-party parliamentary system in which the two largest political parties of opposing political ideologies unite in a coalition government. The term is most commonly used in countries where there are two dominant parties with different ideological orientations, and a number of smaller parties that have passed the electoral threshold to secure representation in the parliament. The two large parties will each try to secure enough seats in any election to have a majority government alone, and if this fails each will attempt to form a coalition with smaller parties that have a similar ideological orientation. Because the two large parties will tend to differ on major ideological issues, and portray themselves as rivals, or even sometimes enemies, they will usually find it more difficult to agree on a common direction for a combined government with each other than with smaller parties.
Occasionally circumstances arise where normally opposing parties may find it desirable to form a government. One is a national crisis such as a war or depression, where people feel a need for national unity and stability that overcomes ordinary ideological differences. This is especially true where there is broad agreement about the best policy to deal with the crisis. In this case, a grand coalition may occur even when one party has enough seats to govern alone. An example would be the British national governments during World War I and before and during World War II.
Another possibility is that the major parties may find they have more in common ideologically with each other than with the smaller parties, or that the fragmentation of the smaller parties is so great that no other coalition is stable. Examples include Austria, where the mainstream parties of the left and right have often formed grand coalitions to keep parties of the far left or far right out of government (an example of a cordon sanitaire), or Israel, where no single party has ever won enough seats to govern alone, and, in some parliaments, the fragmentation and intransigence of some of the smaller parties has made it easier to maintain a coherent platform with a grand coalition than with a narrow one. This is often done out of political necessity, to prevent an early election.
In post-war Austria, a "grand coalition" (German: Große Koalition) between conservative Austrian People's Party (ÖVP) and the Social Democratic Party of Austria (SPÖ) has been the standard case of governance for most of the time since the end of World War II. Notable exceptions have been Josef Klaus's second government (ÖVP alone 1966-70), and the governments of Bruno Kreisky (SPÖ alone 1970-1983, SPÖ-FPÖ 1983-1987), Wolfgang Schüssel (ÖVP-FPÖ 2000-2005, ÖVP-BZÖ 2005-2007), and Sebastian Kurz (ÖVP-FPÖ 2017-2019, ÖVP-Grüne 2020-present).
After the Velvet Revolution, there has been a government of socialists (?SSD) with Prime Minister Milo? Zeman supported by the right-wing ODS. It has been called the government of "The opposition deal".
In the European Parliament, the two main pan-European party groups are the European People's Party (EPP) and the Socialists & Democrats (S&D). Until 2019, they held a majority in the European Parliament and worked together in a grand coalition. However, advances by green, liberal and right-wing populist parties across Europe in the 2019 European Parliament election led to the EPP-S&D coalition losing their majority.
In post-war Germany, "grand coalition" (German: Große Koalition) refers to a governing coalition of the two largest parties, usually the Christian Democrats (CDU/CSU) with the Social Democrats (SPD). While Germany has historically tended to favor narrow coalitions of one of the two largest parties with the FDP or with the Greens, four grand coalitions have been formed on a federal level: the Kiesinger cabinet (1966-1969), the First Merkel cabinet (2005-2009), the Third Merkel cabinet (2013-2018), and the Fourth Merkel cabinet (since 2018). Under the Weimar Republic, a grand coalition was one including all of the major parties of the left, center, and center-right who formed the basis of most governments - the SPD, the Catholic Centre Party, the German Democratic Party (DDP), and the German People's Party (DVP). The two examples were the first and second Stresemann cabinets (August-November 1923) and, less ephemerally, the second Müller cabinet (1928-1930).
Iceland has a grand coalition since 30 November 2017 between the largest parties of the centre-right to right-wing Independence Party (16), the left-wing Left-Green Movement (9), and the centre-right Progressive Party (8).
In Italy, "grand coalition" (Italian: Grande coalizione) refers to the only supermajority government formed in April 2013 between center-left Democratic Party (PD), center-right The People of Freedom (PdL) party, and the centrist Civic Choice (SC) and Union of the Centre (UdC) parties. In November 2013, The People of Freedom (later renamed as Forza Italia) however dropped out and broke apart, leaving the Letta Cabinet and further Renzi Cabinet (Coalition between PD, NCD, SC and UdC) with a small majority.
The UK has had grand coalitions in central government during periods of wartime. They are referred to as the "National Government".
The Northern Ireland Executive, the devolved administration of Northern Ireland, combines the largest Republican (also predominantly left of centre) and Unionist (also predominantly right of centre) parties. The chief post, of First Minister and deputy First Minister, is a diarchy. Most recently, this coalition was led by the Democratic Unionist Party and Sinn Féin.
All parties, major and minor, are offered posts in the executive, although may now opt to form an opposition.
In the Netherlands, there have been several cabinets which can be described as grand coalitions. The Roman/Red coalitions of the 1940s and 1950s under Prime Minister Willem Drees were composed of the catholic Catholic People's Party (KVP) and the social-democratic Labour Party (PvdA) at its core and several smaller parties as backup (Drees-Van Schaik). The Purple coalitions in the 1990s under Prime Minister Wim Kok were between the Labour Party (PvdA), the conservative liberal People's Party for Freedom and Democracy (VVD) and the social-liberal Democrats 66 (D66) party (First Kok cabinet). The Second Rutte cabinet a grand coalition cabinet which also can be described as a purple coalition was composed of the People's Party for Freedom and Democracy (VVD) and the Labour Party (PvdA). A more traditional grand coalition cabinet was the Third Lubbers cabinet, comprising the christian-democratic Christian Democratic Appeal (CDA) and the Labour Party (PvdA).
In Spain, the term "grand coalition" is typically used to refer to any hypothetical government formed between the centre-right to right-wing People's Party (PP) and the centre-left Spanish Socialist Workers' Party (PSOE). No such a coalition government as ever been formed at the national level, though it was proposed by then-Prime Minister Mariano Rajoy during the 2015-2016 government formation process. Rajoy's own investiture on 29 October 2016 was allowed through the abstention of PSOE's MPs in what was dubbed as a "covert grand coalition", in reference to PSOE's tolerance of Rajoy's minority government through punctual agreements until the re-election of Pedro Sánchez as party leader in June 2017.
At the regional level, grand coalitions between the two largest parliamentary forces have been rare, but examples exist:
Additionally, both PSOE and PP formed a joint coalition government--which also included other parties--following a successful vote of no confidence on the Cantabrian regional government of Juan Hormaechea in 1990, enduring until the 1991 regional election. At the time, however, the PP was not among the two largest political parties in the regional assembly.