As an aside to my post on the UK's move to fixed-term Parliaments and a supermajority to call an early election, I should point out that while we don't yet have fixed term Parliaments, we have already made a similar change to the UK. Back in 2006, the then-Governor-General Silvia Cartwright staged a quiet revolution, announcing in a speech that the power to call elections is covered by the "caretaker convention". Which means that if a Prime Minister is defeated in a confidence vote (e.g. as a result of coalition collapse), they can't just call an election. Instead, they become a caretaker Prime Minister while Parliament has a chance to form an alternative government. An early election is only called if the majority of the House supports it.
The reason for this is pretty obvious: the people have elected a Parliament. Our will in who makes up that Parliament should be respected. Prime Ministers shouldn't just be allowed to make us vote again if the results turn out to be inconvenient for them.
Except of course, they still can, because the above rule only applies to Prime Ministers who have actually lost a confidence vote. A Prime Minister who still retains the confidence of the House is free to call an early election, either to thwart an upcoming confidence motion or at the time of maximum electoral benefit. While we have a strong political norm against this, enforced by the electoral punishment of parties who go early, that's not enough. Which is why we need to legislate for a fixed parliamentary term. We elect Parliaments to represent us, and our will should be respected. The politicians should just have to lump it.
