Whether Cameron was giving an honest answer to a straight question, or whether he had decided to head off speculation about his retirement after an EU referendum (if he wins in May) or whether he shot his mouth off without thinking, is now beside the point. He has thrown the whole Tory election campaign off the rails. Nobody is sure that it can be got back on track, although politics being what it is, there is still everything to play for.
Unfortunately he is the victim of his own idea to legislate into existence fixed term parliaments, when the whole evolved system depended on the very flexibility he has now closed down. This is because the UK has a parliamentary democracy using the powers of an absolute monarchy with only one elected chamber functioning under a regime of tension between the executive and the legislature. A fundamental feature was the power of the prime minister to go to the country for a mandate whenever he judged the moment right, either because the government was riding the crest of the wave of public opinion or because it had lost a vote of confidence. Now and again prime ministers carried on until the maximum five years was reached and quietly left to be defeated in the election which followed.
The reason for these arrangements are complex and confused, but they have to do with the fact that the government is the Queen’s but the members of it have to come from parliament which is charged both with holding it to account and enacting its legislation. The uncertainty of the prime minister’s intentions acts as the catalyst which gives the whole process form. The fixed term parliament has not really worked and it is clear it should have gone a year ago, or at the latest in the autumn of 2014 and the fixed nature is at odds with the absolute flexibility of the constitution in general. A fixed piece of a flexible whole is usually a fault requiring repair in any system or mechanism.
This whole episode, based on a harmless remark underlines this. We either have to go back to all the uncertainties and flexibilities of our fabled unwritten constitution, or we have to have a proper written one, approved by the people, by which rules government is carried out. Meanwhile the consensus among those who profess to know is that Cameron has shot the whole Tory party in the foot. We shall see.