I tend to agree with Baboonery. Whats so great about a fixed term Parliament. Surely if a government is unable to get its legislation passed, then its time for them to seek a fresh mandate. You cant have different criteria for different types of vote. Either its 55% for everything or 51% for everything.
I'm no proponent of fixed parliaments - I rather prefer the British system where a Prime Minister can call it when he likes when he thinks he has the most chance of getting elected.
But didn't the people say they were sick of these politicians in it for themsleves, doing what's best for them? At least with a fixed term parliament, parliaments are dissolved for the right reasons.
You can have different criteria for different types of vote. In the Scottish parliament it's 50% plus one for no confidence and 66% (according to BBC) or 75% (accroding to SteveB).
I think Baboonery had a valid point when he said that laws (the 55%) shouldn't be made just for a specific coalition on a specific parliament. There should be more of a principle than that, and therefore maybe 66% would've been better.