A rotation government or alternation government is one of the ways of forming of a government in a parliamentary state. It is a government that, during its term, will see the individual holding the post of prime minister switch (or "rotate"), whether within the same political bloc or as part of a grand coalition. Israel has seen by far the most experience with such a governing arrangement. The governments of Ireland and Bulgaria are now in their first rotation agreement. Usually, this alternation is guided by constitutional convention with tactical resignation of the first officeholder to allow the second to form a new government. Israel, which established the rotation mechanism in 1984, codified it in 2020.
, rotation governments have been formed in Ireland, Israel, Malaysia, North Macedonia, Romania, and Turkey. Successful rotations have only taken place in Israel (first with the rotation between Shimon Peres and Yitzhak Shamir, and second with the ascension of Yair Lapid to the office of the Prime Minister of Israel on 1 July 2022, fulfilling the agreement of his coalition government), Ireland (with Leo Varadkar returning as Taoiseach in December 2022) and Romania (with the rotation between Nicolae Ciucă and Marcel Ciolacu in June 2023); in all other cases, either the rotation has not yet taken place or the government has collapsed before it could occur. A rotation government was considered after the 2005 German federal election.
Bulgaria
Greek mythology
In the writings of Diodorus and the Bibliotheca of Pseudo-Apollodorus, Oedipus's sons Eteocles and Polynices agreed to share the kingship of Thebes, switching each year. When Eteocles's first year as king ended, he refused to give up the kingship, exiling Polynices, who found allies in Argos to retake the city, recounted in the events of Seven Against Thebes.
Germany
After the 2005 German federal election, a rotation government between the CDU and the SPD was considered; under it, then-incumbent SPD Chancellor Gerhard Schröder would have continued to serve until 2007, at which point the CDU's Angela Merkel would take over for the remaining two years. The CDU rejected this and opted for a grand coalition without rotation, with Merkel holding the Chancellery for the entire term.
Ireland
After the 2020 Irish general election a coalition of Fianna Fáil, Fine Gael and the Green Party was formed on 27 June 2020 on the basis of a rotation government. Micheál Martin of Fianna Fáil became Taoiseach with an agreement that Leo Varadkar of Fine Gael would serve as his deputy (Tánaiste) until December 2022, when he would become Taoiseach. The rotation took place on 17 December 2022, with Varadkar sworn in for his second non-consecutive term as Taoiseach, and Martin taking the role of Tánaiste.
Israel
Israel was the first country to employ a rotation government ( memshelet rotatzia) in 1984, following the negotiations for the forming of a grand coalition government after the inconclusive 1984 election. The 1984 rotation deal was non-binding; de jure, the rotation government was two successive governments, one formed in 1984 and headed by Alignment's Shimon Peres and another formed in 1986 and headed by Likud's Yitzhak Shamir, but whose membership and portfolio distribution were otherwise identical. In addition, since the 1984 rotation government was formally two "ordinary" governments, the prime minister could unilaterally dismiss ministers from the alternate prime minister's bloc: In fact, Shimon Peres forced the Likud finance minister, Yitzhak Moda'i, to resign, despite Shamir's objections.
In the 2015 Israeli legislative election, the Zionist Union originally floated the idea of forming an intra-party rotation government between its co-leaders Isaac Herzog and Tzipi Livni, in which Herzog would serve for the first two years and Livni for the second two, though Livni announced on 16 March 2015 that only Herzog would serve as prime minister of a Zionist Union-led government.