Indeed it was Labour's legislation, but a) it had the chance of doing what it said on the tin, which this doesn't, b) was installed as a general principle to last beyond the length of that parliamentary term, which this (by the coalition's admission) isn't, c) was created for a new parliament, not one with centuries of procedure and tradition d) contained a 28-day blow-up, which this doesn't.

Most countries that have fixed term parliaments have no equivalent to a 55% rule - the idea that such a move is necessary is just spin. They don't have such a rule because they settle for the fact that regaining political stability via elections when parliament is up the spout is more important than the great god of fixed electoral terms. I don't agree with fixed terms anyway - I think the benefits they give are minimal – but I think this is a silly way to go about enforcing them.

Besides, it's rubbish PR.