There are many good ideas that were not in our manifesto; it is important that we, as politicians, are able to adapt and to reflect the times.
It is not the case that the Fixed-term Parliaments Act was introduced simply to maintain the coalition. The previous system, whereby prerogative power was exercised over a democratic process for political advantage, served the wrong interests. Imagine Gordon Brown sitting in Downing street in 2007 chewing his fingernails and trying to decide whether that was the right time to call an election so that he could have another five years in government.