His candour on both subjects, the election and his future, breaks the convention of governments and prime ministers.
He made the comments in an interview with The New Zealand Herald about the year ahead, given before he left for his summer holiday in Hawaii.
The timing of the Rugby World Cup, which starts on September 9 and ends on October 23, limits the Government's options over the general election but it is still common for governing parties to say nothing about the timing - in order to leave their opponents guessing.
''I would be very reluctant to go early,'' he said when asked what reason there could be for going earlier than November.
''You can never say never, but my view is that the electoral cycle [three years] is quite short. In return for a relatively short cycle, the voters expect you to go the distance.''
Mr Key's comments will be immensely helpful to Labour.
He also said he had made it reasonably clear that he did not want to go back to Opposition leader again.
''I don't think it suits me as a person. I'm not a negative person and a lot of Opposition is negative.''
Mr Key said the 2011 election would be challenging because ''essentially there is no money''.
''There won't be money for us and there won't be money for Labour.''
