Cohabitation (sometimes called co-participation) is the situation that occurs when the independently elected Head of State of the Republic is of different political party and does not form a coalition where the Head of Government has to be accepted by the parliament. This situation occurs sometimes in semipresidentialist republics such as France, Portugal or Peru, when the President of the Republic is of different political party than the majority of the members of the parliament, because that political system requires that the President name to a Prime Minister acceptable by the majority party of the parliament. By extension it receives such denomination when two opposite parties are forced to govern jointly in a government of national unity, or between a national president and a mayor or governor of the state capital for its political and usually demographic importance, like for in Mexico, where the head of government of the Federal District (with more than 20% of the population of the country) has been since 1997 a party other than the President of the Republic, or in the case of Argentina where the governor of Buenos Aires Aires (a demographic third of the country) has been on several occasions of a party opposed to the central government.
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