Whenever there are two leadership contests for the party in power within any single parliamentary term then it should be mandatory that a general election is called
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This gives the people the chance to choose to accept or not, the mandate put forward by the latest leader who would become prime minister. The situation would occur whenever the elected prime minister has to stand down, for whatever reason, and his/her replacement also has to stand down in the same term A third prime minister would have to put their proposed mandate to the people along with the proposed mandate from other parties in a general election.